I used to run XRS but had some problems with it recently, and I think the buffing part of it was removed? It disappeared for me anyway.
Basically I really liked the system in XRS where I could make little icons for the main class buffs and it would shows me how many people need each one.
Hovering an icon shows me names of who is missing that buff in a tooltip.
Clicking it tries to buff someone who is currently missing that buff (if it's a spell I can cast).
Shift-clicking it reports to the raid who is missing that buff (useful for spells that I can't cast).
Each button was filtered by class so AI didn't look at Warriors/Rogues, etc.
I had it setup with PW:F, DS, SProt, AI, MOTW and that was all I needed and it was perfect.
We're a casual Kara guild, I don't need huge windows or grids of exactly what buffs everyone does/doesn't have (like in BigBrother). I don't need flask checking, food checking, Pala buff checking, and I don't want to spam the raid every time I want to know what's missing. Six icons with numbers was perfect and took up no screen space while still always being visible and easy to glance at.
Any suggestions for something similar? Or how can I get this working in XRS again?
XRS has worked fine for me pre- and post-2.4. Did you accidentally remove your config file or delete the buff buttons or something? (That's the part I love the most about it, so I'd definitely notice if it went missing or didn't work. As I said, though, XRS is working great for me.)
It might be a slight pain, but I'd probably try deleting the addon completely (and your savedvariables file for it) and install the latest from files.wowace.com and reconfigure it. It might be overkill, but it's worth a shot if yours isn't working properly.