Much the same way Microsoft has Exchange as its server backend and Outlook as the client UI, Lotus has Domino as its backend and Notes as its frontend. Domino i

Much the same way Microsoft has Exchange as its server backend and Outlook as the client UI, Lotus has Domino as its backend and Notes as its frontend. Domino is a pretty good product. It's fast, secure, distributes well, was one of the first products to employ a document-based database, and it's backwards-compatible across something like fifteen years of its database format. Every sysadmin I know loves it. Notes, in contrast, is now a wretched mess, having failed to correct for fifteen years' worth of poor UX decisions. Taken as two independent entities, the calendaring in Domino is excellent. Notes makes it a pain to deal with, but Domino does a good job of solving the hard bits. So there's a good argument to be made that Lotus has made a successful go at this, but I wouldn't give Notes the credit.