I wonder if anyone wrote a free or open source version of Lotus Notes? I think IBM stopped supporting it after a while. It is a shame that IBM bought out Lotus and couldn't keep the Lotus software current and up to date.
A local newspaper used Lotus Notes to serve up stories on their website, before Python Django replaced it.
I was going to link to IBM Lotus Symphony[1] in response to your question but it turns out it's only tangentially related to Notes, sharing some marketing names and, eventually, included with Notes (version 8 I think).
Symphony was initially proprietary, then freeware and finally, in 2012, turned over to the ASF as a donation. It basically consisted of a typical spreadsheet, word processor, presentation suite all using ODF as a document format.
So, not what I thought I would find but still slightly related to your question...
Hah, yeah, that's a good way to put it. For some reason I had it in my head that Notes got carried along with Symphony but it turns out it was the other way around with Symphony being given away as a free add on to Notes.
I had the "pleasure" of using a Notes/Domino solution back in the mid 90's but it was only for a couple of months; when I joined they were most of the way through a migration to MS Exchange/Office. Can't say I loved/hated it with the same zeal as other posters, just didn't have enough time to form an opinion at the time.
A local newspaper used Lotus Notes to serve up stories on their website, before Python Django replaced it.