http://www.perlmonks.org?node_id=1006502


in reply to On the fly syntax checkers in emacs, ultraedit or vi

Komodo got it from Emacs, its called flymake-mode

see emacs wiki or sourceforge

But be aware of downsides: Vulnerabilities when editing untrusted code... (Komodo)!

searching for "flymake YourEditor" will show you more alternatives.

Cheers Rolf