Complex sentence: Elance maintains a current list of their overall top 100 in-demand skills, and in 2011, the most in-demand skills were PHP programming, WordPress programming, article writing, graphic design, and HTML programming.
Split into simpler sentences: Elance maintains a current list of their overall top 100 in-demand skills. In 2011, the most in-demand skills were PHP programming, WordPress programming, article writing, graphic design, and HTML programming.