I'll start off by saying that i'm pretty impressed with this piece of software.
It works well and has clean feel to it (unlike most opensource software I run into).
I have not yet installed it myself but have been intensively using the demo.
I personally feel your strongest advantage is the fact that all of your features have been well thought out to allow it to be used for any general purpose (not leaning strongly towards a single purpose of use).
You should definitly should keep that up.
I hope to not ever see this software being bloated with features that serve only a very specific usage scenarios (unless they're modulair).
Now for example I plan to use opengoo for developing software.
I have run into a few things on the demo which I feel could make it easier in general.
-Folder/Category support in the documents tab (i'm aware tags can be used to achieve categorisation, however I can not sort according to them.)
-"My overview" page, where a user can actually see tasks that have been appointed to him for that day.
-Task email notifications
Other then that I think this piece of software can serve all my needs.
Keep up the good work,
You currently risk getting a donation from me in the near future.
Ps. seems that the "new task" button sometimes breaks on the demo version
