I've been using Lite-C for many years. I have a friend who was interested in doing some kind of algorithmic trading and I wondered about using Zorro. How easy/difficult is it to transition from Lite-C/SED to Zorro? I've never programmed in *actual* C language, so is it more or less the same? Can I use SED to write scripts for Zorro?

The other suggestion was to use MQL4, which I've never heard of.

Being experienced in Lite-C helps a lot, so it shouldn't be that hard to write your first Zorro script. Zorro supports Lite-C and C++, see https://zorro-project.com/manual/en/started.htm Lite-C is pretty much the same as C.

The workshops in the manual, see https://zorro-project.com/manual/en/tutorial_var.htm for the first one, are a good starting point.

You can use SED as well as any other text editor to write scripts, but the Notepad++ editor that comes with Zorro is much better than SED.