If you haven't, heres a user exercise. Go to xcode and see what you can get done with an NSTabView... go head, I'll wait.
If you want a hint, here is what you can do.
Rasmus Andersson
you are my new hero.Rasmus is the primary developer for Kod - a Mac based programmers editor. As part of Kod, he has developed a project called Chromium-Tabs, which basically gives programmers a nice - easy to use - API for creating beautiful browser like tabs (some say they look like Chrome).
So, I've promptly made a makefile so I dont have to deal with that nasty xCode IDE (yuck!), and integrated the Chromium-Tabs framework into my CodeAssistor project. Now I have a nice beautiful looking TABBED editor :)
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All in all, the makefile took me 5 hours, and learing-integrating chromium tabs into codeassistor took 14/15 more.
If you want to play with the Alpha release of 0.0.8 (Mac Only so far), here you go
EDIT: Kod and Chromium Tabs Source