I love writing my mails and blogposts in Writeroom and I’ve been a big fan since I found out about it around 3 years ago. Yesterday though, I switched sides and bought Byword after I read Roberto’s post. From his blog:
I already switched from WriteRoom when Byword came out for longer writings, but with Markdown support, this is now the tool.
Roberto had tried to make me adopt Markdown when we were in Oslo, but the lack of built in support in Writeroom was always the showstopper for me. Now there is no excuse and I decided to give it a try. Loving, Byword & Mardown, so far.
Might try QuickCursor in a few days as well.

