Useful Math Site

It’s been a while since I’ve written about science here.
Recently, I’ve had need to exchange rather complicated math formulas with someone via email.
Sending formulas like

is difficult to do clearly via email, as there’s no real means of formatting one’s text with math markup.
Fortunately, there’s LaTeX, an excellent typesetting system that is the de facto standard for marking up documents containing math. I hear it’s also common in the publishing industry, but have no personal knowledge of that industry.
For a long message, it’s probably easier to create a LaTeX document and attach it to the email, but my messages are often less than a page, and that is a bit of a hassle. Sending the raw LaTeX markup via email would also be unsuitable. That assumes the other person (a) has the software installed to read it, and (b) the time to copy-paste the code into their program and render it.
Similar problems exist for computer programmers, and the pastebin service exists as a highly effective way of exchanging programming code with other users. Surely there’s a similar thing for math and science folks, right?
Turns out there is: the Mathbin site allows one to enter text marked up with LaTeX and display it to others without any installed software. Very handy.