latex4technics is described as 'Online LaTeX editor with autocompletion, highlighting and 400 math symbols' and is an website in the Education & Reference category. There are three alternatives to latex4technics, not only websites but also apps for Windows, Linux and Mac. The best alternative is TexitEasy, which is both free and Open Source. Other great sites and apps similar to latex4technics are Codecogs (Free Personal) and Papeeria (Freemium).
HTML LaTeX equation editor that creates graphical equations (gif, png, swf, pdf, emf). Produces code for directly embedding equations into HTML websites, forums or blogs. Images may also be dragged into other applications like Word. Open source and XHTML compliant.
Write and compile LaTeX online. You need only browser and Internet access to typeset LaTeX documents and compile them to PDF. Papeeria mobile works with iPad, iPhone or Android, so you can work on your texts even when your are far from your desktop or laptop.