It's dawned on me that actually 64-bit still isn't being pimped as much as it should be for the benefits it offers in terms of potential speed increases, reliability and optimisations, so I want to use this thread to list all the software you know (or might not yet know of) that has a 64-bit version available and links to any additional plugins needed for them. You can include beta releases as long as they are stable, being optimised and will be kept up to date.

Archiving:

WinRar x64 (64-bit)
7-Zip for 64-bit Windows x64 (Intel 64 or AMD64)


Browsers & Addons:

Internet Explorer 9 64-bit - native to Windows
Chrome 64-bit - was in Beta, support ceased
Safari 64-bit - currently only available for Mac
Firefox win64-x86_64 - only available through nightly builds currently (seems very stable though)
Adobe Flash Player 64-bit - includes 32-bit
Java JRE Windows x64 (64-bit) -  you still need 32-bit seperately
Silverlight 5 Developer Runtime for Windows (64-bit)


To be kept updated...