I see two recent items on the web about Mathematica and the rosettacode.org site. One was a Wolfram Inc. corporate blog post, and the other a post on Wolfram's relatively new community site.
There are many items on the page of tasks still without a submitted Maple implementation. It would be nice to see interesting implementations of some remaining tasks, as contributions from the Maple user base. The tasks remaining are of very mixed difficulty levels.
To date there are only 132 entries on the page for Maple implementations of that site's programming tasks. (Of these about 40 were submitted by one member while about 80 were submitted by another member.)