HackStore is a Mac App Store alternative that exclusively lists free software. Listings are free for developers too, and while this is also true for freeware developers who use the Mac App Store, what HackStore provides differently is a download portal not subject to Apple's often-criticized app approval process.
While it's a noble idea, the implementation is still somewhat lacking. Adding a new app to your system through HackStore is a two-stage process: download and installation. The download part worked just fine for me; if it stopped there I'd be happy as a clam. But it doesn't - it tries to install the application on the system itself, resulting more often than not (for me) resulting in HackStore becoming unresponsive and the downloaded file irretrievable. As a result it's primarily useful for app discovery rather than installation.
The application may be of particular interest to developers, as the "store's" content has a focus on code- and system-tweaking utilities.
Sam's Protip: A couple of the games in HackStore are Windows games wrapped in Wine wrappers. I suppose that's OK, but users should at least have the disclosure of what's native and what's not before they download what's basically a whole operating system.