The pi-calculus is a mathematical formalization of concurrent programs in the same way that lambda calculus is a formalization of computable functions. It is basically a notation that allows you to easily specify concurrent programs, and then rigorously reason about them.

I just followed the guidelines when submitting - i.e:

> Otherwise please use the original title, unless it is misleading or linkbait.

It's regrettable that π looks similar to n, however I think it's a very minor issue that is resolved the second that you click the link.

Only if you use terrible fonts.

In college I was fascinated by the Join calculus, in particular it's research implementation in Polyphonic C# and its successors.