If you're familiar with Lotus Notes/Domino, I'm sure SharePoint, in many ways, feels like a déjà vu. But because we don't cover the Notes client or the Domino server (well, not on its own, though we cover several IBM Lotus products that run on top of Domino), I've never really compared them head-to-head.
I was discussing this with my colleague Apoorv Durga today, and rather than focus on the resemblances,
- Notes/Domino comes with a mail server; with SharePoint, you need to add Exchange (but SharePoint and Exchange are much less integrated with each other than the Domino components, and in fact, they sometimes compete for the same collaborative scenarios.)
- A technically inclined person can quite easily build impressive forms-based processing in Notes/Domino. In SharePoint, you really need a .NET developer much more quickly than you'd think.
- But if you do start developing things, it's hard to get your Domino applications past the initial "rapid prototyping" stage -- most custom applications in Domino start out as something that's quickly whipped up, and then keeps being modified. (They're also notoriously difficult to maintain once the original creator has left your company.)
- SharePoint is much more developer friendly; Visual Studio is a very capable development environment, and though Notes/Domino does have development tools, they're comparatively basic.
- And on a very technical level: the Lotus NSF "databases" are not relational. There is no way to do a JOIN with Lotus "tables" (they're called "views" in Domino). Really. It's impossible to do a look-up in a list field to another field in another list. If you think that's some incredibly technical detail that's not very crucial, well, try to create a view of all of your employees, with one field that displays their phone number (taken from another list). You can't, and I've seen several Notes/Domino developers on the brink of a breakdown trying to get around this. By contrast, SharePoint stores everything in MS SQL; it's really easy to do lookups within a list field.
[Update: 07 December] Sorry about the comment on IBM phasing out Notes/Domino, which obviously didn't come across as it was intended. I've therefore decided to delete it (or rather, for the sake of transparency, to leave it there but to strike through.) My colleague Tony Byrne has added some more thoughts about Lotus and SharePoint here.
Meanwhile, thanks to those who contributed technical insights in the comments. I have some follow-up questions that I'll address there.