Linux Intranet Application and Collaboration Software?

_blueboy asks: "I work in IT at a medium-sized Life Sciences company, and we are in the process of developing an intranet. As one of the primary developers, I have been involved in evaluating both development and server software. We are currently using an all Microsoft setup but it has proven to be very finicky, unreliable, and unpredictable. Our director is currently evaluating Domino R5 but several of us would like to move to Linux and Apache. Our director likes the idea that Notes & Domino form a "complete package". I know that Lotus is planning to ship Notes & Domino for Linux soon. Does anyone have any experience with the Lotus software and how well would it likely run on Linux? Are there any similar packages for *nix/apache or any companies that might provide a similar custom built solution? It is essential that the software be able to provide us with easy and reliable document sharing/collaboration tools for a Windows network. "