Online raid management tool?

[Mirawen]

I'm trying to work out a proper solution for my guild to handle raid sign-ups. The in-game calendar barely has any functionality that I'd like (such as pre-defined permissions, allowing all officers to change addons), setting pre-defined class balances required for the raid, DKP weights, etc.

I've found multiple tools googling around, but nothing that's been updated in the past year.

Any help would be appreciated!

Edit: I greatly prefer hosting the system myself; whether it's Python, PHP, Ruby etc. supported doesn't matter.