DEFinition CONtrol Markup Language (DEFCON ML) is written entirely in Java. DEFCON ML derives information in databases, files, network feeds to create web pages. Kind of a WEB Application type.
Web Application Manager (WAM) is written in PowerBuilder with some C code. WAM manages the applications that DEFCON ML delivers.
By the way, SQL stands for Structured Query Language. It is a standard language that works across many (not all) databases. All major vendors support the SQL standard. MSSQL is a database vendor, like Oracle, Sybase, IBM, etc. Many people confuse those two terms thinking SQL is MSSQL.... two different things.
Although I have extensive experience with SQL (you can't really work in PB without learning at least a little bit of SQL) it is mostly on the programmer side of things. Stored Procedures, Triggers and a ton of SQL code. My experience is lacking on the administration side of things... although I get by with it.
I also write C, mostly for handling file manipulation on the lower end of things. C is close to the operating system. Every OS has it's own version of C. Since I work across Windows and Linux a lot, I don't code much in C. That's because C code has to be compiled on the operating system where Java code runs on top of a Java Virtual Machine (JVM). That means I can write my code on a windows box and port it over to linux. The same code runs on both because they each have different JVMJVMs.