EditPlus - A great, extendible text editor with syntax highlighting for basically any markup or programming language (HTML, C, Java, etc. etc.). Basically supports absolutely everything and you can create your own user shortcut tools (e.g. to compile and run programs).
7-zip Totally free zip/unzip program that properly handles files like .7z and .tar.bz which many other programs foul up. I think the latest version of PowerArchiver is either adware or a trial version.
WinMerge - an awesome tool which allows you to compare different versions of a file to see the changes that happened.
FileZilla - no relation to Mozilla, but it’s a free, multi-featured FTP program that works great. Of course, RPGC staffers get to use WS_FTP Pro for free, ‘cause good ol’ Mr. Sat got us a mass product license.