What type of software (preferably internet-based) would you like to see an open source version (or a different type of open source version) of? Webhosting checkout / billing panel Image hosting script? Website design software? Ad serving (phpadsnew type script with built in checkout)? Search engine? Media site (video uploads / funny pictures / arcade / etc)? Social networking / bookmarking (like phpfox)?
I would like to see (but not going to happen) open sourcing of ubersmith as its a fantastic product but there are a few things I would like to see added to it which for the developers would be a low priority but would help to integrate everything together
How about a DECENT and FEATURE FILLED web control panel? Something along the lines of cpanel or plesk. Zpanel tries to do it, but development is slow and features are extremely limited. You can see it at http://thezpanel.com
How about a icecast/shoutcast control panel? Off the top of my head I don't know of any free ones, only commercial ones.