I wish to grant Shell access over HTTP (using a web browser) to a few of my users. Is there a utility, preferably free, which I may use to enable it.
The no. of users are approx. 100 and I want separate shell sessions for each of them, and the web interface should require them to login with their user/pwd credentials.
Ajaxterm is nice and reasonably simple to set up.
As I can't comment yet, I'll post this as an answer: Please make sure to setup https (SSL) if you use Ajaxterm for a SSH session. All the SSH-encryption won't be of any use if the traffic between your browser and the webserver isn't encrypted. You'll find a "Howto setup https" further down the Ajaxterm-page posted by Alex.
The webmin suite (http://www.webmin.com/) has this (and far far more, if you're interested)
I know this question is kind of old at this point but it is still showing up in lots of Google search results so I thought I'd provide an updated answer:
Gate One (HTML5 Terminal Emulator/SSH client): http://liftoffsoftware.com/Products/GateOne Gate One source code: https://github.com/liftoff/GateOne/ ...and here's a video overview if you like that sort of thing: http://www.youtube.com/user/LiftoffSoftware
Gate One has many advantages over the other answers but this isn't the place to enumerate them. Just see the links above for the details.
Full disclosure: I am the author of Gate One.