What tool can I use to allow multiple teams to share files?

I need to work with several teams and need to be able to share requirements and design documents. Most people won't be too technical, so I want to avoid source code tools. The main requirements are:

1. Easy sharing via links. I don't want people to have to install multple tools just to see a file or learn anything about svn checkout.
2. Permissions - I want to allow view only access to most people, with some having add/edit permissions. I don't want anyone to be able to permanently delete anything.
3. Revision History - I want to see who has added and edited files and be able to revert to previous versions.

I've tried Dropbox and SkyDrive, but they each have faults. Dropbox allows users to permanently delete files, and it will even delete the file from your local machine when it is synced. SkyDrive doesn't allow enough fine grained permissions or revision history. Do I need a CMS system like Drupal]? Would Sharepoint be the proper tool? I don't necessarily need an open source solution. The easier it is to set up and administer, the better开发者_高级运维.

Just my personal bias, but I hate Sharepoint. (I see this Q is tagged Sharepoint)

I much prefer some sort of Wiki, and have had good experience with TWIKI. It certainly meets the three basic requirements.

AFAIK Dropbox never deletes files "permanently" but you can undo it via the web interface. If I remember correctly you also can restore old versions of files but I cannot try it right now.

Adobe Buzzword might do most of what you are looking for.

If you do not need online document creation, a traditional CMS is not really what you are after. Drupal could serve your purposes, but it would not be straightforward- afterall, file attachments are second class citizens for a web content system.

Alfresco is a system I've heard used as a competitor for Sharepoint and useful for managing documents.