Mojo SDK for webOS development, but the floodgates have finally opened with an opportune leak of Mojo to Torrent-vill. Naturally, Palm will still be locking out unapproved developers from releasing their creations to the App Catalog for the time being, but this should hopefully give the everyman a chance to hone apps in anticipation of a day of approval -- and should really beef up the homebrew community in the meantime. The other good news is that Palm is actually adding developers to its "early access program" at a fairly rapid pace, announcing that it doubled its membership this week, and plans to double it again next week. It's all coming together.
[Thanks to everyone who sent this in]
Update: The original leak was strictly Windows-style, but PreThinking notes that it's available for Mac now as well.