Anyone interested in total languages might like Idris, Agda, or Coq:

• https://www.idris-lang.org/

• https://en.wikipedia.org/wiki/Agda_(programming_language)

• https://en.wikipedia.org/wiki/Coq

In particular, some interesting approaches to services with an indefinite lifespan (like a daemon) were explored with codata in Agda:

• http://wiki.portal.chalmers.se/agda/pmwiki.php?n=ReferenceManual.Codatatypes
• http://www.cs.swan.ac.uk/~csetzer/slides/wessexSeminarMarch2009.pdf
• http://lambda-the-ultimate.org/node/4818

Anyone interested in total languages might like the Charity language:

https://en.m.wikipedia.org/wiki/Charity_(programming_language)