Developer Semi Secret announced that the Indie iPhone Holiday Sale, the recent Christmas promotion discounting a six independent and celebrated iOS titles to $0.99 each, has so far raised over $25,000 for the Child's Play charity -- the sale lasts for a couple more days, too, so you can still buy Canabalt, Ellis, Drop7, Solipskier, Spider, and Osmos real cheap!!

To celebrate this milestone, Semi Secret has made Canabalt's source open and available, allowing curious developers to download and tinker with the game's code, graphics, sound effects, music, and Flixel for iOS. The code is taken from the game's latest version, which includes optimizations for 60 FPS performance on iPad/iPhone 4 and proper retina support.

The studio's Adam "Atomic" Saltsman posted the following with the announcement:

"Canabalt has been a crazy ride for us. It's helped keep the lights on and pay for our health insurance, and allowed us to take the kind of risks that indie devs love to take. But, in the spirit of the Humble Indie Bundle, the holidays, and a (likely) bout of temporary insanity, it's time to open our trenchcoat and show everybody what we've got going on under there!

DISCLAIMER: We wanted to offer our condolences to everyone who downloads this and goes poking around in there. This was a rushed Flash game, ported, in a rush, to the iPhone, before iPads or iPhone4s even existed. We try very hard to stay up to date and do good work, but we're just two dudes -- it's possible if not likely that some of the way we do things is not ideal or optimal."

Saltsman also shared some interesting stats for Canabalt, revealing that the game has so far sold over 225,000 copies! You can download Canabalt's source and read more about its release at Semi Secret's site.