Ludum Dare 30 is happening! Before the event, feel free to vote on a possible theme at the Ludum Dare site. This is not necessary for event attendance, but it’ll give you an idea of possible themes.
There are two events happening in the Ludum Dare, one of them is the compo and the other is the jam. Tim, long time RunJumpDev member, explains it best with this description:
48-hour solo competition: you have to work alone, base your game on the theme, use only assets you produce over the weekend (see rules for exemptions), use only new or publicly-available code (you can reuse old code, just publish & post it on the LD blog!), and publish your source code (any license, including all rights reserved). If you want to see more information on the specifics of the compo, check out the compo rules page.
72-hour jam: way more relaxed. You can work alone or with others (enter your solo game here if you need more time), use any libraries or middleware, any assets you have license to use, and you don’t have to publish your source.
Here is a list of tools you can use for the Ludum Dare, supplied by several RJD members: