while you decide which language for next project, you should care about

1. Is the language supported on the platform I will work on?
2. Is the lauguage good for the nature of my project? For large scale system, a strong typed language is highly desirable. For multi-thread system, concurrency control is a must.
3. How hard is the lanugage to learn? Is it close to any language I am already familiar with?
4. How is the library support? Is it complete enough for my project?
5. Do I need any framework? How deep is the learning curve?
6. How active is the development community behind the languages/APIs/frameworks?
7. Any similar systems that have been implemented in the language?