What are some alternatives?
When comparing zipBoard and GroupDocs, you can also consider the following products
UserSnap - Usersnap Track is your central place to organize user feedback and collect bug reports. One screenshot is all it takes. Get rid of endless email exchanges and coffee-stained sticky notes. Your new life is awaiting you!
FileAgo - Secure file storage and collaboration solution for teams
Jira - The #1 software development tool used by agile teams. Jira Software is built for every member of your software team to plan, track, and release great software.
Microsoft OneDrive - Secure access, sharing & file storage
BugHerd - BugHerd: The Visual Feedback Tool for Websites
TeamWox - TeamWox is a groupware system designed to optimize the business management.