This is what it says in the Desura Terms of Use:
QUOTE:
2. Use and ownership of user provided content
If you send to Desura, or upload to the System, any content of any type ("Content"), including forum posts, commentary, ideas or suggestions whether or not solicited, then: by uploading the Content you license the Content to Desura as set out in this clause 2; and you must ensure that you are the owner or creator of that content or have received permission from the owner or creator to make such submissions and to licence that content as set out in this clause 2.
You expressly authorise and permit Desura to exercise and to authorise others to exercise all of the rights comprised in copyright and all other intellectual property rights which subsist in the Content and you irrevocably consent to all such exercises. Desura is not required to compensate you or any other person in any manner for any such exercise or authorisation. In particular, Desura may use, reproduce, modify, create derivative works from, distribute, transmit, broadcast, and otherwise communicate, and publicly display and perform the Content and other works which are based on them (including by way of adaptation or derivative works) in any form, anywhere, with or without attribution to you, whether or not such use would otherwise be a breach of any person's moral rights, and without any notice or compensation to you of any kind. This clause does not limit Desura's privacy obligations under clause 10.
All Content and Applications added and managed by Publishers is governed by the terms and conditions agreement which they must accept prior to publishing their Applications on the System.