Udemy has put together an infographic that compares Ruby, PHP and Python. This looks (briefly) at the history, popularity, ease of use, demand for programmers, benchmarks and more for each language. If you're job-hunting, Udemy says that you probably want to know PHP above Ruby or Python.

According to Udemy, Python is the "most-discussed" language, followed by PHP and Ruby. The rankings come from IEEE Spectrum's analysis of IRC discussions. Udemy also looks at the TIOBE Index, where PHP outranks Ruby and Python.

For job data, Udemy polls several sources. On Craigslist Udemy finds PHP in the lead with 21% of the listings. Ruby slinks in at 3%, and Python isn't even on the graphic. (JavaScript is listed at only 9%, but one suspects that it's going to be in fairly high demand in 2012.) On Monster.com, Udemy finds 305 postings as of December 12, 2011. Ruby has 138 listings, and Python only 79. On LinkedIn, Udemy finds nearly 19,000 folks with "PHP developer" in their descriptions, 720 folks with "Ruby developer" and 1,316 people with "Python developer."

I do wish the Udemy graphic was a bit clearer in terms of what they mean by "lines of code" and what was being tested for the "average run time" results. They did lead me to the paper by Klaus Purer comparing PHP, Ruby and Python, though. If you haven't read it, it's slightly dated now (released in 2009) but worth a read anyway.