There seem to be quite a few fabulous web-sites now that compile LaTeX online.

I was wondering what techniques these sites used to speed up compilation of documents. It would seem they would be particularly interested in reducing the CPU load from loading the compiler, especially as many of the documents they would be asked to create would be relatively small.

In my experience it seems like the ordinary process for creating a relatively small document with LaTeX, especially XeLaTeX, seems to take a substantial amount of time starting the compiler (e.g. a couple seconds), and a relatively very modest amount of time running it (a few milliseconds).

It would seem then that one could gain tremendous improvements in performance  for relatively small documents by running (PDF/Xe)LaTeX as a daemon that produced a number of documents without having to restart the process.

Others seem to have tried this, and it has been discussed (also) on Tex.SE before. The techniques seem to be somewhat dated, and in any case I couldn't get them to work on Linux with XeLaTeX (which just happens to be what I'm using).

Are any of the online compilers using a sort of TeX daemon to compile their documents in the background? Are there any other recent developments in this area? I happen to be personally interested in the XeLaTeX on Linux, but I would love to know more about what is happening in the LaTeX performance area.

There also seems to be quite a bit of discussion about pre-compilation (as seen under eg performance), but I tried it and the benefits do not seem to be as great as that of daemonizing the process (though I would stand to be proven correct!).

Are there other techniques these online services may be using to improve the response time of compilation?


Question: I need help! PopUp with only OK button
Answer: Mobile Safari will disable the browser controls (new tab, back, etc.) when a JavaScript popup is opened. Unfortunately, this locks the browser until you press "OK" or "Cancel" (if available).

To get rid of the popup without clicking "OK" or "Cancel":


If you are in Mobile Safari, close it by pressing the home button.
Kill Mobile Safari by double-tapping the home button to bring up the bottom panel, tapping and holding the Mobile Safari icon, and then tapping the minus sign (-) at the top left of the icon.
Open the Settings app.
Click on "Safari".
Click on "Advanced"
Uncheck/Turn off "Java Script"
Go into Flight mode or turn the Wlan off
Open Safari and close the tab (of the former bugging popup - it wont open this time, because JavaScript is disabled :-) )
Turn Wlan and Java Script on again
enjoy the lack of the stupid popup in your Browser. ;-)


So this way you dont have to clean your cache.