In Charm++ some keywords have lower case "ck" (eg: ckout,ckNew) while other have upper case "Ck" (eg: CkPrintf, CkExit, CkArgMsg). Is this just the syntax or does it have any significance too?
I am new to Charm++ and this is something I was thinking about.
It's just the syntax.
Broadly speaking, things were named in what seemed like the least surprising way (e.g. ckout being lowercase to match what std::cout looks like, classes like CkArgMsg starting with a capital), but there are certainly inconsistencies in how things are named in Charm++. We're (note: I'm one of the Charm++ developers) slowly cleaning up things like this and are adding more C++ish naming schemes (like ck::*) to new features we develop, but for now, it's one of Charm++'s idiosyncrasies.