Very neat! Suggestion: add a 'flags' field where you can specify stuff like -std=c99 and any other flags you might need for your code to compile, and a horizont

Very neat! Suggestion: add a 'flags' field where you can specify stuff like -std=c99 and any other flags you might need for your code to compile, and a horizontal rule or something like that after every line of input code. If you do the 'flags' thing make sure you filter it to avoid escapes to the underlying shell.