I'm looking for software to handle appointment calendars, contact
lists, and todo lists.

Yes, I realise I may not find an ideal one. I'm open to wriging my
own if necessary, or (prefereably) modifying others' open-source
versions, (or even more prefereably) finding one that is already ideal.

What I'd like it to do, besides the obvious ones of storing my data and
letting me edit and dispay it.

* I should be able to use it on Devuan.

* Ideally, it should use replicated data. Like the way distributed
revision control is used to replicate source code. Yes, I'm willing to
handle merge conflicts manually on sync, but I do want to be in control
of merging and possible race-conditions.

* I don't want to need aways-on network connectivity,

* I don't want to depend on Google's calendar services, but I'd like to
be able to use them to coordinate with other people who do.

* I'd like to be able to use established protocols rather than inventing
my own.

* I'd like to be able to access it on android as well as plain desktop
Linux. (The desire for android compatibility will drop away if I
ever get a plain-Linux phone). (This could be a web interface)

* I'd like the system to be simple in concept and execution. No bloat,
no incomprehensible frameworks, etc.


Any ideas?

-- hendrik