I have been a Trillian fan since the company introduced one of the first Instant messenger that tie messengers together. This is an application download you get the best of both worlds you can install the client and use it to connect to Yahoo, MSN, and AIM. While others have come along such as jabber, and others trillian still holds a soft spot in my heart.
Its a great thing when you can log in all the messengers you want including IRC then only use one application. No longer do you need to download Yahoo messenger, MSN messenger now Live messenger, AIM messenger, and ICQ messenger they are all in this one program. Oh and I forgot to tell you it’s FREE the Basic version, there is a Pro version and if you like Trillian I encourage you to purchase the Pro version.