You can post any questions you have about developing a channel here. Taking a look at the media browser website, looks like it is a server? If so, it will probably need to provide the following to the Roku player:
REST or other http api for requesting content from media
XML (ideally) or JSON feed of content
Content in h.264 AAC format - this may require real time transcoding and streaming to the Roku using HLS or Microsoft Smooth Streaming
Aside from that, you have the options of using the built in UI components or rolling your own to display the content on the device and interact with the user.
- Joel