Is there an open-source program that will let me manage the content on my Sansa e250R mp3 player?

The one that came with it is not only buggy and prone to crashing, I have lost the login information. At this point I am disinclined to dig it up again – this is my device and I should be able to manage it how I want to, without logging into some precious music store that I never shop at.

Windows Media Player will sync playlists to the device, but won’t let me add or remove content therein without wiping and reloading everything.