Version 3 Beta - iTerm2
iterm2.com/version3.html
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
There are dozens of new features. Many bugs have been fixed. Performance is significantly improved. The look and feel has been updated. Applescript support has been updated, but it's not backwards compatible.