The picture isn't very clear, but I'm almost certain the plant on the left is NOT a Christmas cactus.. It looks more like an etiolated Cotyledon tomentosa "bear paws", or some kind of Kalanchoe. The one at the right should be an Echeveria or Sempervivum, again close up and better quality pics needed to identify

Both looks like they need a LOT more light, especially the Cotyledon... Cactus mix is okay for short term, but definitely not for the long run, your plants are also prone to rot in that mix. Easy fix would be 50/50 mix of perlite and the cactus soil; if you want best results then look into a gritter soil mix, i.e. adding gravel, grit, or coarse sand.

David is correct on the ID for the left plant and gave great advice!

Aw thanks spapa! :)