Now I'm making new cryptocurrency CodableCash. It uses Ticket PoS consensus algorithm, therefore priority of development environment is ease of development and manage code.
Java Programming Language
Java is very excellent programming language, and it has a lot of programming tools like Eclipse, JUnit.
Most important thing to make a cryptocurrency is testing environment. That is the most difficult part. JUnit is very easy tool to make the environment.
In addition to Testing, code management is also very important. Java is object oriented programming language, so it is possible to make abstract class and extend it.
About performance, CodableCash don't need heavy calculation. The exception is nonce calculation for delay time.
Performance overhead in Java is loading class, and threading, comparing with C++. But simple calculation is not so slow. Sometimes it is faster than C++ and C. And by using cache, we can cover the weak point.
Eclipse IDE
Eclipse is one of greatest graphical IDE.
I'm planning to delegate testing to many people, so IDE is necessary to make set up process easy. I'm going to put source code as Eclipse project on Github.
Github and Travis
Github is most popular opensource repository. Travis CI is good tool to execute automated Testing.
I'm going to build development environment at first, and start actual development after that.