As of October 2015, DMC floss conversion charts are on the websites for DMC, Cyberstitchers and Annie's Craft Store. DMC has a PDF chart that displays equivalent color numbers for DMC's rayon and satin flosses.
Cyberstitchers has several conversion charts, including some that compare DMC floss to Anchor, J & P Coats and Sullivan flosses. Clicking on a link between DMC and another manufacturer opens a new page that shows color numbers for both companies.
Annie's Craft Store compares colors between DMC and Anchor flosses. The conversion chart contains standard colors that are organized by DMC number. In addition, the chart displays variegated and metallic flosses.