Using CVS through PHP

I'm looking at building a system script for build management. I would very much prefer to do this in PHP. Are there any integrated means of using CVS with php, or am I limited to using system calls from cvs? Thanks, Wes --------------------------------------------------------------------------- The selection and placement of letters on this page was determined automatically by a computer program. Any resemblance to actual words, sentences, or paragraphs is pure coincidence, and no liability will be assumed for such coincidences. ---------------------------------------------------------------------------