I have been involved in freight system, messaging systems in telecommunications, and business automation. I have also developed an expert system in learning Motion in Physics for a doctorate thesis presented in the Physics International Convention in 1994.
During college, I have used x86 assembly, C, Pascal, Clipper extensively. After college, I ventured into C++, Powerbuilder, C#, and Java. I also learned relational databases, database design and modeling, and SQL. I have used Sybase SQL Anywhere, Microsoft SQL Server, Oracle, PostgreSQL, MySQL, and SQLite. I found the Software Engineering Book of Knowledge (SWEBOK) strawman version online and it led me deeper into software engineering and the IEEE standards.
I am focusing now on C++ which started before the C++0x standard. The D programming language had also caught my attention more than a decade ago and had been playing with it from time to time.