In the low-level front, I've used Assembly, C, C++, and willing to learn Rust or D, or Vala.
These days all my new code is written in F#, although I still need to touch a lot of C# code.
And I'm willing to learn TypeScript or Elm in case I need to do some web+frontend development.
Or Ceylon/Kotlin (along with RoboVM if iOS is needed) or Swift (when it becomes opensource), in case I want to do mobile apps.
In regards to databases, I'm an old-school guy who thinks normalized data usually beats any NoSQL solution, except for rare BigData cases.
If you require consulting work, I'm generally available for hire.
Q&A for professional and enthusiast programmers
Q&A for computer enthusiasts and power users
Q&A for professional programmers interested in conceptual questions about software development
Q&A for Bitcoin crypto-currency enthusiasts
Q&A for Ubuntu users and developers
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Q&A for road warriors and seasoned travelers
Q&A for system and network administrators
Q&A for power users of Apple hardware and software
Q&A for active researchers, academics and students of physics
Q&A for enthusiasts and power users of the Android operating system
Q&A for linguists, etymologists, and serious English language enthusiasts
Q&A for users and developers of hardware and software for Raspberry Pi