Checksum for LinuxWell, it's done, basically. Currently it's in alpha, and only brave souls will want to play with it, so there's no web page, no download, nothing! But there is working code, and if you want to play with it in this state, mail me, and you get to be one of the first beta testers.
There's no installer or anything like that; here's what you get..
A Bash script - this is the main Checksum program. It uses the built-in *nix hashing tools to create and verify the actual hashes, and either kdialog or zenity for the GUI elements (or both, in hybrid mode). Although designed to be activated via service menus, it also works fine in a shell. Checksum's behaviour can be modified be either switches or named symlinks, whichever you prefer; generally it's completely transparent.
Service menus - these add extras to your right-click menus so you can checksum and verify files, folders and volumes directly from within KDE (Konqueror, Dolphin, etc). I've also created a few custom optional menu items, i.e. "Checksum Music Files". Feedback on which of these you like best, is welcome.
And full instructions! Basically, you will need to drop things in, and setup file types by hand, though this is fairly easy to accomplish. The whole install shouldn't take more than a minute or two on KDE (KDE4+, KDE3.5 or less is not and will not be supported, at least intentionally).
I have no knowledge of Gnome, though I do intend to make Checksum Gnome-friendly, so if use Gnome and want to help get Checksum running sweet on your desktop, definitely get in touch.
Anyways, I just wanted to let you know Checksum for Linux exists, has already had a good few TB of testing, and is working very well, albeit spartan-like, which is actually more how I originally envisaged checksum for Windows. This time around, I aim to remain true to that form - although all the main Checksum goodies are there; one-click hash or verify, MultiHashing™, generic .hash file handling, configurable file masks, MD5/SHA-* support, Intelligent appending, read-only fall-back, etc.; I don't plan to go to any great lengths to have Checksum hold user's hands - if you want to do crazy stuff with Checksum on Linux, it will let you!
Checksum for Linux is free and open source, GPL v3.
So there you have it; notified; and if you want to get on board, simply mail "linux" at this domain.
ps. I almost forgot! Checksum for Linux also comes with a "Windows HashFile Converter", which basically switches out the DOS line breaks and back slashes of all hash files (and playlists, optionally) in a path, so they can be used on a *nix system. Although trivial, it is capable of converting an entire drive at once, which is handy. Of course, checksum for windows will still be able to handle the hash files just fine, afterwards.