Regex Crossword

I'm going to phone this one in, sort of, because it's an entire site of puzzles. Regex Crossword is a twist on the traditional crossword concept. In each cell you have to enter in a character that satisfies two or more regular expressions that apply to the cell in question. They start out really trivial but start to get very difficult later on. This is the last one I solved and holy shit was it ever tough:

I'm hooked. Go check these out.