Prototyping is a great way of making games. You make lots of small, quick prototypes, and iterate on them to "find the fun". Scripting languages like Python and Lua are really useful in this process and there are lots of nice libraries like Pygame to assist in the process.
It would be cool to be able to include players in the prototyping loop so that your game ideas can be tried out infront of an audience and get feedback early in the process. The democratisation of game design, I guess.
I've been thinking about this a lot lately, especially as I've been going through the frustrating process of trying to get my recent gamejam entry to work under Windows. It's a pygame based game which should port trivially, but it's still a fair bit of hair-tearing work. It's not much fun to have to do such a huge amount of laborious work just to get your game ideas infront of people so that they can play them, and tell you what they think.
To this end I've been working on the Javascript game library which I wrote about earlier. Recently my efforts have been in separating it from the processingjs library into a standalone system which will run on all the major browsers. Firefox, Safari, IE6, IE7 are currently tested and working.
Hopefully you'll be seeing more links like this on here in future:
Download a zipfile of the source of the JSGameSoup library here:
http://mccormick.cx/dev/blogref/jsgamesoup-30.zip
Or check out a branch with bzr:
bzr branch http://mccormick.cx/dev/jsgamesoup/
Patches welcome!