The Channel Manager Channel is the via-the-uportal-gui means for initially publishing channels, or updating publishing information.
Stylesheet cache purge
The Channel Manager includes a link that, when clicked, causes uPortal to purge its XSLT stylesheet caches. Normally XSLT stylesheets are cached. If you update the stylesheet associated with a channel, that change won't take effect until portal restart. Bummer. You might not want to have to have a whole restart just to change the way a particular channel renders. Instead of waiting for a restart of the whole portal, you can click this link and uPortal will purge its stylesheet cache and re-read the XSLT the next time it is needed. This allows you to patch the stylesheets of a running portal without taking down the whole portal and to more quickly see the results of a change in a development environment. (You can also configure uPortal not to cache stylesheets at all, useful for quick feedback on changes in a development environment.)
What alternatives do I have to using this channel? What might I consider in choosing how I manage channels in my uPortal?
An alternative to using the Channel Manager is using channel publishing fragments and the pubchannel Ant task. Some people prefer to use this Channel Manager Channel because they like its GUI and workflow, find it a sane way to edit a running portal, etc. Other people prefer to use the Ant task and channel publishing fragments because they prefer to store and version channel publication in a file repository.