I've just put this online at
http://www.ribosi.com/index.php?main_page=softwiki Sign up for a free account to add and edit software. There's no catch, the only reason I require a log in is for administrative control. Also as a control, everything must be approved before it's allowed to go public. I did this merely to stop spam and software that doesn't belong. Software doesn't have to be open source to be included, but it does have to run on Linux. As time goes by and I'm able to see just what controls are really required, I foresee opening this up a bit.
It's brand new, so there's very little software in it now. By my own efforts, this will continually grow. With some community involvement, this will change drastically.
The main feature of this wiki is the ability for users to search a Windows application and see alternatives for Linux. So, someone searching a Windows alternative of "MS Word" might get a response of Abiword, OpenOffice.org and Kwrite.
There's still some backend work to finalize, but nothing that would stop software from being entered now, which is why I put it online. I'll be polishing it out for the next week or so (don't worry, I do my work on a non-live server) doing things like adding software comments and I'm playing with the idea of BBCode support. Still, if you encounter bugs, please let me know about them using the contact form on the site.
*edit
Since a whole 2 people have signed up to add software - and only one of them has actually added anything, I've opened this up so you don't need an account to add to the wiki. We'll see how this goes.