Digsby multi-protocol chat client seriously cuts RAM usage
Early builds of Digsby have been known to eat over 100MB of memory. If you've got 4GB of RAM, that might not seem like much. But if you have an older PC with 1GB or less, there's no reason that a messenging program should eat up 10% or more of your memory.
A few days ago, Digsby pushed out a new alpha release that addresses the memory issue. I find that the alpha version tends to hover around 30MB of memory use, and according to the developers, it shouldn't go much higher than 50MB even if you register a ton of email and social networking accounts.
The new version also features other performance enhancements, and improvements that will attempt to help you get around firewalls and proxy servers if necessary. There's also a new crash reporter.
Keep in mind, the latest version of Digsby is still in alpha, which means there are likely plenty of bugs to be worked out. Normally I wouldn't recommend replacing stable software with an alpha. But if you've been frustrated with Digsby's high resource usage in the past, you should really check out the latest version. Just make sure to backup your settings first.