Glances is "a CLI curses based monitoring tool for GNU/Linux and BSD OS". It uses Python and PsUtil.
Hacker News thread about it.
The thread has some positive comments about Glances.
EDIT: Sorry, readers, about the temporary multiple posts on the same topic. Due to getting some Blogger error, I clicked Submit a few times, so multiple posts resulted. I've deleted the duplicate posts now. The duplicate posts only existed for a few minutes before I deleted them, but mentioning it because I don't anyone to think I'm spamming them.
- Vasudev Ram - Dancing Bison Enterprises