About 5 minutes after releasing my first WordPress theme, Theseus, upon the world, I had my first support ticket to deal with. Check it out:
Thank you for this awesome theme, but it doesn’t seem to be working for me.
This is what it says after installing and testing it.
Parse error: syntax error, unexpected T_VARIABLE in /home/javitsin/public_html/wp-content/themes/theseus/index.php on line 1
Now a Parse Error happens when, essentially (I say essentially, not exactly, because I’m a designer not a programmer), you make a typing mistake in a PHP file. Thing is, I hadn’t made any typing mistakes—that I could see.
The problem is, I work on a Mac and Macs handle line endings, you know, where you press return, differently than everyone else. Different as in, make Unix computers explode. Unfortunately for me, a lot of web servers are UNIX computers. That explode.
If you’re using Smultron, the open-source Mac text editor, here’s how to fix your WordPress theme, changing Mac line endings to Unix line endings, and stop the explosions. Open the preferences pane and navigate to Open & Save. Down there at the bottom, tucked away neatly is the life or death Line Endings setting, probably set to “leave unchanged”. Change it to Unix.
And that’s it! No more explosions.
ThemeShaper 
Thanks for the info Ian. I haven’t ran into this issue with any of my themes, but I will have to check my settings in Smultron. Smultron is my second favorite editor just behind Coda now!
I think I have Coda envy.
It’s pretty sweet. I am sure the wife wouldn’t mind if you tell her you really need it!
Enter: Vim.
Ian, I really look forward to ThemeShaper mail in my inbox. You’re doing a bang-up job.
Thanks, Daniel!
I tried Vim once and it scared me. I need my precious Mac GUI. 🙂
I use Smultron on my Mac for all my amateur attempts at web template design. I want to start creating WP templates and this little gem of advice has probably saved me from giving up before even getting started. Thanks for sharing.