I'm using emacs on my Chromebook by using crouton.

Slightly off topic but I've never understood why people use Crouton. Surely if you buy a Chromebook you do it for the software, right?

I bought it for an excellent user environment for everything but programming, that could alt+tab into a programming environment. All of my non-tmux work is inside a browser. It made sense to me that I would have an environment that rapidly (less than 3 seconds) boots from cold to Chrome with optional Linux environment when I need it. It has advantages of being automatically encrypted and having deep integration with Google Apps that I use every day.

Thank you for your great answer . I am also considering buying Chromebook because my case is almost same as you (everything is inside of chrome or inside of bash ) , but I am a little skeptical about crouton , Do you have(or know) any video for showing/introducing how it works on Chromebook , how multiple tab's in bash works , I know this question is little wired but I haven't seen any crouton on chrome book yet , So I am very curious . Can it replace my ubuntu machine ? ( because I use it just for chrome(web) and heavy terminal usage (bash , gcc , gdb , emacs , etc), and I don't use any gtk qt etc app). Thank you .

As for replacing your ubuntu machine, the default distro is 12.04, but I'm sure you can install the latest.

I don't know about the amount of shell tabs you can have (as I use tmux), but my short experiment seems to hold up well.

The only problems I think you'll face is the scary 'OS Verification' at startup and limited memory (but can be solved by using a SD card). croutons are cheap to install so install, remove, install until you find your niche.