Local custom library

If you are asking about possibility of creating libraries, be it local or online, it's definitely possible. Else there wouldn't be extensions like Motionbro around. This would take knowledge of javascript, xml, html, to write extensions. However, it's all up to our own individual skill level and what we can do with what we know. I would just like to ask, if u are bringing up the idea of cloud, does this mean that you have more than one workstation and need to access your files on more than one location? If you do not want to upload to cloud, the only way is to carry a copy of this library with you on a hard disk wherever you go. If not, would dropbox suffice?

Not really, but you can of course use Bridge to sort, tag and categorize your assets and projects.

Mylenium