If you want something highly customizable, you should checkout EMACS Org Mode http://orgmode.org/ http://orgmode.org/ (a major mode in EMACS). There are various

If you want something highly customizable, you should checkout EMACS Org Mode http://orgmode.org/ http://orgmode.org/ (a major mode in EMACS). There are various integrations between it and other TODO + calendar apps. An example of org to google calendar: http://orgmode.org/worg/org-tutorials/org-google-sync.html http://orgmode.org/worg/org-tutorials/org-google-sync.html