Recently there was again a discussion about how to get the Arduino IDE running on an Ipad and in that discussion I proposed the idea to have an IDE running on a webserver.
See - Arduino IDE on the iPad - #8 by robtillaart - Libraries - Arduino Forum -
This morning I came across - What are Online Compilers & Online IDEs? - CodeProject - which discusses (not in depth) the topic too, and was for me the trigger to create a separate topic.
An IDE on a webserver would allow people to access their sketches from anywhere from any device (in theory), PC/laptop/Mac/smartphone/tablets, even from a networked Arduino (reprogramming itself ?) and as long as the platform has a browser it would be possible. The basic version would be a simple textfield and a few buttons, running the existing compiler etc in the background.
The biggest question imho is how to upload the compiled sketch to the Arduino. I am thinking an USB cable or XBEE connection might do the job at home.
Q: What do you think of this idea?
Q: Is it feasable?
Q: What are the main problems?
Q: Ideas to solve them?
Q: Has anyone done something like this yet?.
Rob
Q: What do you think of this idea?
I think it would be a great project for those with the skills.
Q: Is it feasable?
Don't see why not, but then again I'm a hardware guy and software things are either too easy or impossible depending on the phase of the moon.
Q: What are the main problems?
Probably the uploading the compiled hex code to the board via the bootloader. The arduino serial convertor requires different drivers depending on the OS and which board you are using.
Q: Ideas to solve them?
??
Q: Has anyone done something like this yet?.
??
As a proof of concept, that is very interesting. I think that Code Warrior (or something like that) can work on a server, so everyone can access it (and the number of people at the same time costs more too although it is way cheaper than separate licenses).
And on Arduino's case, the licenses are nothing to worry about, so it would really just be a repository for your sketches in the server.
I think it is possible, but the highest level my programming language skills reach is C, so I have no idea how to do it or if it's easy or not.
For the upload, XBee would work and USB too... uploading through Ethernet... I don't see it coming anytime soon, but who know? 
robtillaart:
Q: Has anyone done something like this yet?.
This is how mbed works. Compiler Tour - Handbook | Mbed
I figured it was because they didn't want to release the compiler. I suppose the advantage is you don't have to port the IDE to Mac & Linux. Other than those, it's hard to imagine what the real advantage of this is.
An IDE on a webserver would allow people to access their sketches from anywhere from any device
We have this now. It's called github.