Hi. Our backend doesn't use latexrender. Although this provided some initial inspiration, our code is very different and a great deal faster. Latexrender is suitable for small scale deployment, our method written in C++ andcompiled for the local machine, which therefore requires root access. Its around 1000x faster and after many years of testing its proving to be 100% stable.

Given you are on a free server, you won't be able to install our backend software. However, there is very little justification for you to make a local installation. What most people do is use the CodeCogs server, but to reduce dependency on us they cache the generated images locally. You can implement this in PHP.

Regarding v2.5 of the Editor. This is no longer available. The latest editor is only available when you purchase a licence. If you are a free, open-source site, and can prove is then we don't charge, except for a small admin fee - really there to help you install and get going. For any other purposes the costs are greater, so see http://www.codecogs.com/latex/purchase.php for details.

Hope this helps.