There are currently 3 releases of Accordian available. Accordian 1.0 is for Windows only while Accordian 1.1 is available for both Windows and Solaris (and you may also be able to port it to other operating systems such as Linux or MacOSX with only modest effort).
Accordian 1.1 on Solaris
So how do you play? The object is fairly simple, you deal the cards out in a line and then try to stack them back up into a pile. To do this you may move a card onto another card that is of the same suit or face value, but only if there are either no cards between them or two cards between them, and you can only move a card towards the front of the line. It seems very simple, but if you're not careful, you will get stuck.
To download Accordian, goto the download page on SourceForge.net and choose the files suitable for your purposes. It's open source and it's free. *Please Note* Accordian 1.1 depends on some Qt 4.0.0 dynamic link/shared libraries, as well as a couple others, which you will need in order to run the program. On Solaris, the way I've compiled it, it should look for the Qt libraries in directory /Qt-4.0.0/lib/. For Windows it should be fine to put the libraries in the same directory as the program. Any problems, questions, or if you think you can make the project better, post to one of the forums, links to which are located here at the bottom of the page, or email firstname.lastname@example.org.
Accordian 1.2 is in progress (slow progress, as I have work and other projects occupying my time as well). The code is Win32 because that is what most people seem to be downloading, probably due to the large dlls required for Accordian 1.1 (Qt version), or alternatively because they just don't know that the "Accordian-Qt" package has a Windows compatible version. Also, I have learned about something called WINE, which can allow Windows programs to run on Unix.