I love NNF for its simplicity! Had some problems getting it to work though:
I first got that T_PAAMAYIM_NEKUDOTAYIM error and had to change :: to -> in domtemplate.php as mentioned in another thread already: http://forum.camendesign.com/php-5-2-and-domtemplate-php-typo-bug
Then I noticed that my hosting returns Apache version 'NOYB' (none of your business) so I had to comment out the check in start.php.
Then I got a completely blank page (no source). I went over the code and found out that I had to rename all occurrences of $LANG since it was already defined as being 'C'. I renamed the variable to $LANGSTR in start.php, lib\functions.php, themes\greyscale\lang.example.php and themes\greyscale\theme.php.
That's it! Hope this helps others having similar problems.