The Axis of Eval

One aspect of reactive demand programming that sets it apart from other reactive programming models is its support for optimistically working with the predicted future states of signals.
Think about a signal that carries the current time in seconds, that you want to display on screen as a clock. The screen should update close to the full second....

Just had a nice insight regarding systems that exchange reactively updating (potentially large, structured) values such as RDP:
The dynamic output of a process is indistinguishable from a static storage resource (file).
In batch systems like Unix, this symmetry is not so deep: the output stream of a process looks somewhat like a file, but the process can't make any changes to earlier, already emitted portions of the stream. This is unlike a file, which can be edited...

What if you want to use a big value, like a whole database table or weblog, as a Reactive Demand Programming signal value? This would make it possible to use RDP to orchestrate things like incremental MapReduce pipelines. Here's one weird trick to make...

Urbit is some kind of new operating system design thingy, that is kinda hard to categorize.
Some interesting design points are:
Urbit restricts the number of identities in the system to 232. This means Urbit doesn't have enough identities even for currently living humans. In line with the usual obfuscation going on in Urbit, such an identity is called destroyer....