Can I upload files on a project?
Of course, as many you want. Just drag files (one or more at once) on the document box in the project editor. If you upload the same file more than once, versions will be created. Uploaded documents will be full-text indexed.
Which users can see those files?
Only the ones that have “document read” permission on that project. Usually project managers and worker, but you can change default permissions. https://twproject.com/support/using-twproject/security/roles/
Can I search uploaded file’s content full text?
Well, depends on the file you uploaded. Pdf, word, excel, PowerPoint, open office, txt, html are all indexed.
Images are not 
Can I link a project to a folder on my file system?
Twproject uses the concept of “file storage” to address this matter. You can have remote file systems, samba, subversion, ftp or amazon s3 “storages” and everyone can be linked to a project. Links can point both to a subfolder, a document or the repository root. Some basic actions like upload, create folder, delete, rename can be done using Twproject interfaces. File storages are accessible with the mobile interface too.
https://twproject.com/support/using-twproject/documents/file-storages/
How permissions work on file storages?
Actually it is quite complex, but summarizing everything is delegated to the permissions the user have on the project linked to that repository. Hi level permissions are necessary to create new repositories, then Twproject security does the dirty job.
https://twproject.com/support/using-twproject/security/roles/
Can Twproject connect to Amazon AWS S3?
Yes. https://twproject.com/support/using-twproject/documents/file-storages/
Can Twproject connect to a subversion repository?
Yes. Moreover it can import SVN logs for generating worklog.
https://twproject.com/support/using-twproject/documents/file-storages/
Can Twproject connect to Alfresco document management?
Yes, Alfresco and most of recent DMS expose repositories using Samba or NFS. Remote file system type can be used directly. https://twproject.com/support/using-twproject/documents/file-storages/
Can Twproject connect to SharePoint?
Yes, see above.
Does Twproject manage versions?
Yes. If you upload a file with the same name (on the same project) a version will be created automatically. From the document page of project or resource you will have full access to older version too. https://twproject.com/support/using-twproject/documents/document-repository/
Can I have my documents on a db instead of the file system?
Yes. By default Twproject use a folder for storing uploaded files. In some cases it could be useful to have that files on the Twproject database. Go to “admin” –> “Basic configuration” –> “File system” and set the “database” type. Existing documents will rest “untouched”.
Can I encrypt my files?
Yes. You can encrypt uploaded files using AES. Go to “admin” –> “Basic configuration” –> “File system” and set the “encrypted folder” type. Existing documents will rest “untouched”.