Program: Sublime Text v2 or 3 (beta)
License: Free to Try, Per-user license or Commercial (currently no enforced time limit, no disabled features)
Description: Sublime Text is a text editor for developing code, using color schemes, highlights, and auto-tabbing/spacing. Sublime Text allows open-source plugins using a package manager to enhance the user experience as well as expand the tools and commands available. While the program is cross-platform, only the Windows release offers a portable version.
Website: http://www.sublimetext.com/
Other: They already provide a portable version for Windows 32/64-bit
That could be a nice addition to the suite.
I hope if one approaches them they will engage.
SublimeText is not open source, but can easily be manually added to your PortableApps setup.
For example, if your PortableApps.com folder is here: C:\Users\JohnDoe\PortableApps\PortableApps.com , then put your Sublime folder here: C:\Users\mmcelheny\PortableApps\Sublime Text Build 3176 x64\