That depends on whether the products they built are "add-ons" or complimentary products. If they're building add-ons (i.e. apart from authenticated users, prem

That depends on whether the products they built are "add-ons" or complimentary products. If they're building add-ons (i.e. apart from authenticated users, premium members can make groups or something like that) then yes, you're getting a conflict of interest. If they'll built a commercial GUI application, or an integrated graphical differ then it will only help develop the dvcs because the ecosystem around it will be larger.