Lotus Notes Client 8.5 3 64 Bit Download May 2026
Let’s be blunt: Lotus Notes 8.5.3 reached end of support (EOS) in April 2018. IBM no longer provides security patches. Running this client in 2024-2025 exposes your organization to:
If you’re reading this article because you’re tired of maintaining legacy systems, consider these options:
No matter your choice, do not let your Notes 8.5.3 deployment rot. The lack of security updates will eventually lead to a breach.
Title: Download Lotus Notes Client 8.5.3 64-bit
Description: Are you looking for a reliable and efficient email client? Look no further than Lotus Notes Client 8.5.3 64-bit! This popular email client offers a range of features, including email, calendaring, and collaboration tools.
Download Link: Unfortunately, we cannot provide a direct download link for Lotus Notes Client 8.5.3 64-bit as it is an older version of the software and may not be available for direct download. However, we can guide you on how to obtain it.
Alternative Solutions:
System Requirements:
Features:
Release Notes: Lotus Notes Client 8.5.3 64-bit is a bug-fix release that addresses various issues reported in previous versions. It also includes some minor enhancements to improve user experience.
Disclaimer: Before downloading and installing any software, ensure you have the necessary permissions and that the software is compatible with your system. Additionally, be aware of any potential security risks associated with downloading software from third-party sources.
Downloading and Installing Lotus Notes Client 8.5.3 64-bit: A Comprehensive Guide
Lotus Notes is a popular email client and collaboration platform developed by IBM. It provides a range of features, including email, calendar, contacts, and task management, as well as integration with other IBM products such as Domino and Quickr. In this article, we will focus on downloading and installing Lotus Notes Client 8.5.3 64-bit, a widely used version of the software.
Overview of Lotus Notes Client 8.5.3
Lotus Notes Client 8.5.3 is a 64-bit version of the software, which means it is designed to run on 64-bit operating systems such as Windows 7, Windows 8, and Windows 10. This version of the client was released in 2011 and is still widely used today due to its stability and feature-rich functionality.
System Requirements for Lotus Notes Client 8.5.3 64-bit
Before downloading and installing Lotus Notes Client 8.5.3 64-bit, ensure that your system meets the following requirements:
Downloading Lotus Notes Client 8.5.3 64-bit
To download Lotus Notes Client 8.5.3 64-bit, follow these steps:
Alternative Download Sources
If you are unable to download the Lotus Notes Client 8.5.3 64-bit from the IBM Support page, you can try the following alternative sources:
Installing Lotus Notes Client 8.5.3 64-bit
Once you have downloaded the Lotus Notes Client 8.5.3 64-bit installer, follow these steps to install the software:
Configuring Lotus Notes Client 8.5.3 64-bit
After installing the Lotus Notes Client 8.5.3 64-bit, you need to configure it to connect to your email server. Follow these steps:
Conclusion
In this article, we have provided a comprehensive guide on downloading and installing Lotus Notes Client 8.5.3 64-bit. We have also covered the system requirements, alternative download sources, and configuration steps. If you are still using Lotus Notes Client 8.5.3 64-bit, ensure that you have the latest updates and patches installed to maintain the security and stability of the software.
Frequently Asked Questions (FAQs)
Reviewing the IBM Lotus Notes 8.5.3 Client (often sought for 64-bit environments) reveals a platform that remains a robust "workhorse" for organizations tied to legacy Domino databases, though it is noticeably dated by modern standards. Overall Rating: ⭐⭐⭐ (3/5)
A reliable collaboration tool for legacy systems, but lacks the agility of modern cloud-based alternatives. Key Strengths Integrated Workflow
: It excels as a "single point of access" by combining email, calendar, and specialized business applications in one interface. Social Integration : This version introduced entitlement to IBM Connections Files and Profiles
, allowing users to find experts and share content without bulky email attachments. Calendar Enhancements : Noteworthy improvements include automatic merging of duplicate entries
and a "counter-proposal" feature that keeps a placeholder for the original meeting time. Enterprise Security
: Known for its "ID Vault" and robust encryption, it remains a go-to for highly regulated environments like banking. The Downside 32bit to 64bit Switch and Upgrade for Domino Server
version of the Lotus Notes 8.5.3 client is a common point of confusion because, technically, a native 64-bit client for this version does not exist. HCLSoftware Lotus Domino 8.5.3 server was available in a native 64-bit version, the Notes client
remained a 32-bit application throughout the 8.5.x lifecycle. It was only much later, with the release of HCL Notes 12.0.2 , that a native 64-bit client was finally introduced.
Here is a guide to getting Lotus Notes 8.5.3 running on modern 64-bit systems. 1. Understanding Compatibility 32-bit on 64-bit OS:
You can install the 32-bit Lotus Notes 8.5.3 client on 64-bit versions of Windows 7, 8, 10, or 11. Windows uses a subsystem called (Windows-on-Windows 64-bit) to run 32-bit apps seamlessly. Official Downloads:
Native downloads are no longer available on public IBM sites as the product has transitioned to HCL. If your organization has an active maintenance agreement, you can typically find legacy installers via the HCL Software License and Download Portal 2. Recommended Installation Steps To ensure stability on a 64-bit machine: Use the location of the Notes.INI - HCL Software
Getting the Lotus Notes 8.5.3 client to work on a 64-bit system is a common task for legacy enterprise environments. While this specific older version is essentially a 32-bit application, it is designed to run natively on 64-bit operating systems like Windows 7, 8, and 10. Key Version & Download Information
Version Status: Lotus Notes 8.5.3 was a major maintenance release that introduced stability fixes and small feature enhancements.
Architecture: There is no native 64-bit version for the Lotus Notes 8.5.3 client; the first official 64-bit client was not released until version 12.0.2. For version 8.5.3, you must use the standard 32-bit installer, which runs under the WoW64 (Windows-on-Windows 64-bit) subsystem.
Current Availability: Since IBM sold the product line to HCL Technologies in 2019, downloads for older versions are primarily found on the My HCLSoftware (MHS) portal. Recommended Setup for 64-bit Windows To ensure the best performance on a modern 64-bit machine:
Install Fix Pack 6 (FP6): This is highly recommended for 8.5.3 as it specifically adds support for Windows 8.1 and includes critical stability fixes for modern environments.
JVM Tuning: To improve speed on 64-bit systems, you can increase the memory allocated to the client by modifying the jvm.properties file, changing -Xmx256m to a higher value like -Xmx768m. lotus notes client 8.5 3 64 bit download
Modern Alternatives: If you are not restricted by legacy server requirements, consider upgrading to HCL Notes 12.0.2 or later, which offers a true native 64-bit client and better integration with current hardware. Comparison of Versions Feature Lotus Notes 8.5.3 HCL Notes 12.0.2+ Architecture 32-bit (Run on 64-bit OS) Native 64-bit Max Memory Limited by 32-bit (~2-4GB) Scalable (>16GB) Latest OS Support Windows 7, 8.1 (via FP6) Windows 10, 11 Status Legacy / End of Life Actively Maintained Is Lotus Notes Still Used by Any Organization? - SysTools
In 2019, IBM sold Notes and Domino to the Indian company HCL Technologies, which followed the same rebranding blueprint, and that' SysTools
While there is no native 64-bit version of the Lotus Notes 8.5.3 client—as this version was strictly built as a 32-bit application—it is fully compatible with and frequently installed on 64-bit Windows operating systems.
A standout feature of the 8.5.3 release is its extended support for large-scale data storage, specifically the ability to handle applications and mail files exceeding 64 GB in logical size. Key Features of Notes 8.5.3
Large Database Support: Supports logical mail and application file sizes beyond the previous 64 GB limit.
Enhanced Search: Features a web-style search bar at the top of the window that allows for quick switches between Notes-style and Web-style queries.
Performance Optimization: This maintenance release focuses on bug fixes and includes "JVM tuning" capabilities to improve responsiveness on newer 64-bit operating systems like Windows 7 and 8.1.
Flexible Data Storage: Users can store full-text indexing information on separate disks from the primary application data to improve performance.
Improved Collaboration: Includes integrated presence and instant messaging, along with sidebar widgets and "Live Text" for faster information access.
Mobile Synchronization: Compatible with Lotus Notes Traveler 8.5.3, which provides automatic client updates and enhanced calendar/mail synchronization for mobile devices. Download and Installation Context
Architecture: There is no separate 64-bit installer for this specific version; use the standard 32-bit setup.exe found in the Installation Guide.
Modern Alternatives: If you specifically require a native 64-bit client, you must upgrade to HCL Notes 12.0.2 or later, which introduced the first true 64-bit architecture for the platform.
Lotus Notes Client 8.5.3 does have a native 64-bit Windows client; it was released as a 32-bit application that runs on 64-bit Windows operating systems. While the Domino Server
has a native 64-bit version, the Notes client remained 32-bit throughout the 8.5.x lifecycle. Download & Availability
Because IBM sold the Notes/Domino product line to HCL Software in 2019, legacy IBM-branded downloads are no longer directly available on the IBM website HCL Software Portal
: Current customers can download legacy versions, or the updated , which has officially succeeded Lotus Notes. Archive Sources : Some users rely on community-shared links
or internal enterprise repositories for the specific 8.5.3 installer. Solid Review: Lotus Notes 8.5.3
Release 8.5.3 is widely considered the most stable "classic" version of the software, serving as a critical maintenance release before the transition to version 9.0. HCLSoftware IBM Lotus Notes/Domino 8.5.3 Maintenance Release
Downloading and Installing Lotus Notes Client 8.5.3 64-bit: A Step-by-Step Guide
Lotus Notes is a popular email client and collaboration platform developed by IBM. Although it's been largely replaced by IBM Notes and Domino, many organizations still use the older versions, including Lotus Notes Client 8.5.3. In this article, we'll guide you through the process of downloading and installing Lotus Notes Client 8.5.3 64-bit.
System Requirements
Before downloading and installing Lotus Notes Client 8.5.3 64-bit, ensure your system meets the minimum requirements:
Downloading Lotus Notes Client 8.5.3 64-bit
To download Lotus Notes Client 8.5.3 64-bit, follow these steps:
Installing Lotus Notes Client 8.5.3 64-bit
Once the download is complete, follow these steps to install Lotus Notes Client 8.5.3 64-bit:
Post-Installation Steps
After installation, follow these steps:
Conclusion
You're looking for a download link for Lotus Notes Client 8.5.3 64-bit. Here are some details and potential sources:
Lotus Notes Client 8.5.3 Overview
Lotus Notes Client 8.5.3 is a popular email client and collaboration platform developed by IBM. This version was released in 2011 and is still used by many organizations today. The 64-bit version is suitable for 64-bit Windows operating systems.
System Requirements
Before downloading, ensure your system meets the minimum requirements:
Download Sources
You can try the following sources to download Lotus Notes Client 8.5.3 64-bit:
Direct Download Link
Unfortunately, I couldn't find a direct, publicly accessible download link for Lotus Notes Client 8.5.3 64-bit. If you're unable to find a working link, consider contacting IBM Support or your organization's IT department for assistance.
Additional Tips
The IBM Lotus Notes Client 8.5.3 remains a critical piece of legacy software for many organizations managing classic Domino environments. Finding the correct installer for modern operating systems can be challenging.
This guide provides a comprehensive overview of the Lotus Notes 8.5.3 client, the reality of 64-bit support for this specific version, and how to safely secure your download. The Myth of the Native 64-Bit Lotus Notes 8.5.3 Client
If you are searching specifically for a native "64-bit" installer for Lotus Notes Client version 8.5.3, it is important to understand the architecture of this specific release.
No Native 64-Bit Client: IBM did not release a native 64-bit version of the standard Lotus Notes Client for Windows in the 8.5.x stream. The client itself is a 32-bit application.
64-Bit OS Compatibility: While the application is 32-bit, it is fully compatible with 64-bit versions of Windows (such as Windows 7, 10, and 11) using the Windows-on-Windows (WoW64) emulation layer. Let’s be blunt: Lotus Notes 8
Native 64-Bit Emergence: Native 64-bit clients for Windows only became standard much later in the software's lifecycle (specifically with HCL Notes 12 and 14).
Therefore, when looking for a "64-bit download" for version 8.5.3, you are actually looking for the 32-bit client installer that runs on a 64-bit OS. Key Features of Lotus Notes 8.5.3
Released as a major maintenance and feature update by IBM, version 8.5.3 brought several refinements to the collaboration suite:
Eclipse-Based Framework: A modern, customizable user interface.
Lotus Symphony Integration: Built-in tools for word processing, spreadsheets, and presentations.
Enhanced Search: Better indexing and faster retrieval of emails and documents.
Side-by-Side Installation: Ability to run the client alongside certain administrative tools more smoothly. How to Download Lotus Notes 8.5.3
Because IBM sold the Notes/Domino product line to HCL Technologies in 2019, the download ecosystem has changed completely. You will no longer find these files on IBM Passport Advantage. 1. The Official Route: HCL License & Delivery Portal
If your organization still maintains an active entitlement or support contract for Notes/Domino, your best and safest route is through HCL. Navigate to the HCL License and Delivery Portal (FlexNet). Log in with your authorized corporate credentials. Search the archive for "Lotus Notes 8.5.3".
Download the package labeled for Windows (often named CZSM6EN.exe or similar depending on the exact package type). 2. The Archive Route (Use with Caution)
If you no longer have an active enterprise contract and require the installer for legacy data recovery, administrators often turn to web archives or community repositories.
Search for Part Numbers: It is often easier to search for the specific IBM Part Number rather than the name. For the standard Notes client 8.5.3, search queries often include part numbers like CI50GEN or CZSM6EN.
Verify Hashes: If downloading from a non-official community mirror, always verify the file's MD5 or SHA-256 hash against known IBM manifests to ensure the file has not been tampered with or infected with malware. Installation Guide for 64-Bit Windows
Since you will be installing a 32-bit application on a 64-bit architecture, follow these steps to ensure maximum stability on modern operating systems like Windows 10 or Windows 11: Step 1: Run as Administrator
Right-click the downloaded executable file (e.g., setup.exe) and select Run as administrator. This ensures the installer has the necessary permissions to write to the Program Files (x86) directory and the Windows registry. Step 2: Choose the Installation Type Notes Client Only: Best for standard users.
Allclient: Includes Domino Designer and Lotus Notes Administrator. Choose this only if you are a developer or system administrator. Step 3: Set Compatibility Mode (If Needed)
If the installer fails to launch on Windows 10 or 11, you may need to assist the legacy installer: Right-click the installer file and go to Properties. Navigate to the Compatibility tab.
Check "Run this program in compatibility mode for" and select Windows 7. Click Apply and try running the installer again. Moving Forward: The Case for Upgrading
While getting Lotus Notes 8.5.3 to run on a modern 64-bit machine is possible, it is highly recommended that organizations look into upgrading.
Version 8.5.3 is legacy software. It lacks modern security protocols (like TLS 1.3), does not scale well on high-resolution displays, and is no longer supported by HCL. Upgrading to HCL Notes 12 or HCL Notes 14 provides native 64-bit architecture, modern security, and seamless integration with contemporary web standards.
To help me tailor any further technical information for you, could you provide a few more details? What operating system are you planning to install this on?
Do you need the standard client or the allclient (with Designer/Admin)?
Is this for active daily use or for archival data retrieval?
The Lotus Notes client, specifically version 8.5.3, is a 64-bit application that was widely used for email, collaboration, and integrated business applications. Here's some information about it:
Overview The Lotus Notes client is part of the IBM Notes software suite, which was designed to provide a comprehensive platform for email, instant messaging, web conferencing, and collaboration.
Key Features
System Requirements To download and install the Lotus Notes client 8.5.3 64-bit, the following system requirements must be met:
Download and Installation The Lotus Notes client 8.5.3 can be downloaded from the IBM website or other authorized sources. Once downloaded, the installation process typically involves:
Support and Maintenance IBM provides support and maintenance for the Lotus Notes client, including:
Please note that the Lotus Notes client has undergone significant changes and rebranding over the years, and version 8.5.3 may no longer be actively supported or maintained by IBM.
The Lotus Notes Client 8.5.3 is a legacy version of the collaboration software originally released by IBM in December 2011. While it can be installed on 64-bit operating systems, there was no native "64-bit client" for Windows in this version; it was a 32-bit application designed to run on both 32-bit and 64-bit Windows platforms. Key Technical Context
Architecture: Version 8.5.3 remains a 32-bit application. It is compatible with 64-bit versions of Windows 7, but may require administrative tweaks to run smoothly on newer OS versions like Windows 8 or 10.
Release Purpose: This version was primarily a "Maintenance Release" focused on bug fixes—addressing approximately 1,200 known issues—along with minor enhancements to the mail sidebar and search functions.
Current Status: This version is end-of-life and no longer supported by IBM or HCL (the current owner of the brand). Users are generally encouraged to upgrade to HCL Notes 9, 10, or higher for modern OS support and security updates. Download and Installation Information
Official direct downloads from IBM's portals are largely discontinued as the product has transitioned to HCL Technologies. Welcome to IBM Lotus Notes
64-bit client for Lotus Notes 8.5.3 does not exist . During that era, the Lotus Notes (IBM Notes) client was exclusively a 32-bit application . While a 64-bit version of the Domino Server
was available for version 8.5.3, the corresponding user client remained 32-bit. HCLSoftware Key Availability Details Architecture Limitation
: The first official native 64-bit Windows client for this software suite was not released until HCL Notes 12.0.2 in late 2022. 64-bit OS Compatibility
: The 32-bit Lotus Notes 8.5.3 client is compatible with 64-bit operating systems (like Windows 7, 8.1, or 10) and runs as a 32-bit process. Official Downloads
: HCL Technologies now manages all Notes/Domino products. Legacy installers are available exclusively to licensed customers through the My HCLSoftware (MHS) portal Recommended Actions If you require 8.5.3 specifically, you should download the 32-bit installer
. If your goal is to utilize modern 64-bit architecture for better performance or memory handling, you must upgrade to at least HCL Notes 12.0.2 HCLSoftware Do you need assistance with the system requirements
for running the 32-bit client on a modern 64-bit version of Windows? 32bit to 64bit Switch and Upgrade for Domino Server
Lotus Notes Client 8.5.3 was primarily a 32-bit application . While it is fully compatible with and frequently installed on 64-bit operating systems like Windows 7 or Windows 2008 R2, a native 64-bit version of the Notes
did not exist for this specific release. 64-bit versions were generally reserved for the Domino Server HCLSoftware Core Technical Profile Architecture No matter your choice, do not let your Notes 8
: The client is a 32-bit executable. On 64-bit Windows, it installs by default into the C:\Program Files (x86)\ directory. Compatibility
: Officially supported on 64-bit platforms including Windows 7 (64-bit) and Windows Server 2008 R2. Fix Pack 6 (FP6) extended support to Windows 8.1 and Mac OS X 10.9. Virtualization
: Scalability testing shows high performance when running 8.5.3 on 64-bit Citrix XenApp environments, particularly with 16GB RAM configurations. Official Download & Access
Because Lotus Notes is enterprise software, it is not available as a general free download for the public. Apple Support Community
There is no official 64-bit version of the Lotus Notes 8.5.3 client. During its lifecycle, the Lotus Notes 8.5.3 client was only released as a 32-bit application. While a 64-bit version of the Lotus Domino server exists for that version, the desktop client remained 32-bit and was designed to run on both 32-bit and 64-bit versions of Windows via compatibility mode.
A true 64-bit client for Notes was not introduced until HCL Notes 12.0.2 in late 2022. Download Sources
Since Lotus Notes (now HCL Notes) is enterprise software, official downloads are typically restricted to customers with active support contracts.
Official HCL Software Portal: The primary source for all legacy and current Notes/Domino versions is the My HCLSoftware (MHS) portal. You will need an authorized login to access these files.
HCL FlexNet: Legacy versions are often hosted on the HCL FlexNet operations portal.
Legacy IBM DeveloperWorks: In the past, "trial" versions of the 8.5.3 client/designer were available via IBM DeveloperWorks, though many of these links now redirect to HCL's support pages. Installation Notes for 64-bit Systems
Downloading and Installing Lotus Notes Client 8.5.3 64-bit
The Lotus Notes client, now rebranded as IBM Notes, has been a popular email and collaboration platform for businesses and organizations. If you're looking to download the Lotus Notes client 8.5.3 64-bit version, here's what you need to know.
System Requirements
Before you begin the download process, ensure that your computer meets the system requirements for Lotus Notes client 8.5.3 64-bit. These include:
Downloading the Lotus Notes Client
To download the Lotus Notes client 8.5.3 64-bit version, follow these steps:
Installation and Configuration
Once the download is complete, run the installer and follow the prompts to install the Lotus Notes client. During installation, you'll be asked to configure your email account and other settings.
Key Features of Lotus Notes Client 8.5.3
The Lotus Notes client 8.5.3 offers several features, including:
Conclusion
The Lotus Notes client 8.5.3 64-bit version is a reliable and feature-rich email and collaboration platform. By following the download and installation steps outlined above, you can easily get started with the client and take advantage of its many features.
Please note that the Lotus Notes client has been rebranded as IBM Notes, and newer versions are available. If you're looking for a more recent version, you may want to explore the IBM Notes 9.x or 10.x releases.
I understand you're looking for a download link for Lotus Notes Client 8.5.3 (64-bit). However, I need to provide some important context and a realistic path forward.
The Short Answer:
You cannot download Lotus Notes 8.5.3 legally from any official IBM/HCL public link anymore. That version is over a decade old, and IBM sold Lotus Notes/Domino to HCL Technologies in 2019. HCL now supports only versions 10, 11, 12, and 14.
The Story Behind Your Search
Back in the early 2010s, Lotus Notes 8.5.3 was a popular enterprise email and collaboration client. Many large corporations, banks, and governments ran their internal systems on Domino servers with Notes clients. The 64-bit version was specifically for Windows 7/8 and later, addressing memory limits of the 32-bit client.
But here’s the reality today:
What you can actually do:
| Your goal | Feasible action | |-----------|----------------| | You have a valid license from an old employer | Contact their IT dept — they may have an internal installer archive | | You need to access an old NSF file | Use HCL Notes 14 (free 90-day trial) — it opens legacy NSF files | | You’re troubleshooting a legacy system | Run the 32-bit version of 8.5.3 (more common), but only inside an isolated VM without internet | | You just need old Notes functionality | HCL offers a free Verse or Nomad web/mobile client for Domino servers |
If you still insist on finding 8.5.3 64-bit:
My recommendation:
Download HCL Notes 14 from the official HCL site (free trial). It will read your old 8.5.3 NSF files without issue, runs natively on 64-bit Windows 11, and is secure.
Would you like step-by-step guidance on using HCL Notes 14 to open an old NSF file from Lotus Notes 8.5.3?
If you're searching for the Lotus Notes Client 8.5.3 64-bit download, it's important to clarify a key technical detail: a native 64-bit version of the Lotus Notes 8.5.3 client does not exist. While the Domino server and certain specific components (like NotesSQL) were available in 64-bit, the standard Lotus Notes 8.5.3 client was developed strictly as a 32-bit application.
However, the 32-bit client is fully compatible with and can be run on 64-bit versions of Windows 7, 8, and 10. Below is a guide on how to acquire, install, and optimize this legacy version for modern systems. 1. Where to Download Lotus Notes 8.5.3
Since IBM sold its collaboration software suite, all official downloads are now managed by HCL Technologies.
The IBM Lotus Notes 8.5.3 client was designed as a 32-bit application. While it is fully compatible with and can be installed on 64-bit operating systems like Windows 7 and Windows 10, a native 64-bit version of the 8.5.3 client does not exist. Download and Access
Official downloads for legacy Lotus Notes versions have transitioned from IBM to HCL Software, the current owner of the Domino portfolio.
Official Source: Active customers with a support contract can download software packages through the HCL Software License and Download Portal.
Package Details: Look for the Notes Standard Client or All Client (which includes Designer and Admin) webkits.
Missing Files: If you encounter issues with customized installations, the missing LotusNotes853.itw file is often required for the InstallShield Tuner. Compatibility and System Requirements IBM Lotus Domino V8.5.3 Downloads | PDF - Scribd
The lotus notes client 8.5 3 64 bit download is a niche but necessary task for IT teams supporting aging Domino environments. While the software itself is reliable for its era, the risks of running an unsupported client demand rigorous security controls and a clear migration roadmap.
If you’ve successfully obtained a verified copy from HCL or your internal archives, follow our installation guide precisely—and prioritize applying Fix Pack 6. For everyone else, treat any download from unofficial sources as a potential threat.
Final recommendation: Use this guide only to buy time. Migrate to HCL Notes 14 or a modern collaboration suite within 6-12 months. Your network security will thank you.
This article is for informational purposes only. All trademarks—IBM, Lotus, HCL, Microsoft—are property of their respective owners. Always verify your licensing rights before downloading legacy software.
Based on the keyword string provided, here is the relevant information regarding the download and availability of the Lotus Notes Client version 8.5.3 for 64-bit systems.