Not enough to be honest. I know a little bit of HTML. Just enough to understand how a webpage is put together and enough to play with the inspect element tool in Chrome. I also know a fair bit of Java, although there are still gaps in my knowledge when it comes to higher end Java programming. I'm currently looking to learn C++ due to it's versatility and also because it's an industry standard.
COBOL, C, C++, Java, Visual Basic - for all the software applications
I have been a computer trainer and software developer too and that is why I know so many of them. Today, I work only on the Websites and as such, I am more familiar with the Internet Technologies as of today.
I began with basic html/css/js in school, building very basic websites back in 2003-2004. Later got into CMS systems like joomla but i did not quite like them. Nowadays I enjoy coding them myself, using frameworks in PHP and Ruby on Rails. You are way more flexible if you just code yourself!