Hosting Detexify costs money and if it helps you may consider helping to pay the hosting bill.
Please fill out this mini-survey! http://goo.gl/forms/K0zoCpfhVq
Anyone who works with LaTeX knows how time-consuming it can be to find a symbol in symbols-a4.pdf that you just can't memorize. Detexify is an attempt to simplify this search.
Just draw the symbol you are looking for into the square area above and look what happens!
The symbol may not be trained enough
or it is not yet in the list of supported symbols.
In the first case you can do the training yourself.
In the second case just drop me a line (firstname.lastname@example.org)!
I am rewriting parts right now and training isn't functional in this version.
The backend server is running on Digital Ocean (referral link) so you can also reduce my hosting costs by using that referral link.
Hosting of detexify costs some money. If Detexify helps you, you might want to help cover these costs.
No. Have a look at http://shapecatcher.com for Unicode.
Philipp Kühl had the initial idea and Daniel Kirsch made it happen.