windows network messenger: yak alternative

been using yak since rupert introduced it. it's very efficient and easy to use. and it's free! the only setback is that there's a limit of 20 users for the free version.

  ...so i went hunting for alternatives and briefly reviewed their interface/function in relevance to what i need.

popmessenger
+ has a good interface; has grouping and broadcast functions
- no multiple selected users chat; only free to try

outlookmessenger
+ good interface
- only free to try

lancechat
+ simple interface
- no multiple selected users chat

lantoucher
- not so good interface;
- no multiple selected users chat

interchat3
- non professional looking interface

achat
+ simple interface
+ can do multiple selected users chat (through chat channels)
+ can send files

so achat it is!