Compiling LaTeX code online

Have you ever needed to make a LaTeX document, without having access to a computer with a latex compiler? My wife had this problem today, and she emailed me and asked me to do the compilation. Of course some things had to be corrected, and we had to do a few email iterations before she was satisfied. Afterwards I started thinking that this must be quite a common problem, and that surely there must be some online service for compiling LaTeX code. And there is!

• This one has quite a nice GUI, and the possibility to output the compiled document in several different formats (PDF, PNG, etc.)
• This one is a lot simpler, but also works perfectly well.