I started using APEX, Application Express, formerly HTMLDB, more than two years ago.
Prior to APEX, anything web related I used Java (J2EE).
When I started at my previous job, they had virtually no internal systems. I was hired as a Reports Analyst/Data Analyst because they had decided their 3rd party vendor wasn't working out.
I somehow managed to talk them into purchasing an Oracle database (SE); since they wanted it quick, and that's what I knew, it was a no-brainer for my boss.
Relatively quickly I managed to nail down my first report after downloading all the data into our shiny new Oracle database. I wanted to impress so I began the tedious task of webifying it, and boy were they impressed.
Up to that point, I had been using a modified version of the Struts framework. It was definitely overkill. I created a bean (class) for the report data and a page (jsp) to display that data. It was a time consuming process at best.
I had read about HTMLDB through AskTom at the job before that one and it was intriguing. So I downloaded it at the new job and took it for a spin. Within a month I had a couple of pages up and running (complete with user login and our cool new graphs). It was difficult initially to wrap my head around the terminology, but once I did it was full speed ahead.
I found the forums on OTN for APEX and began researching problems and asking questions. Soon after that I was contributing. I was hooked.
I was now an APEX evangelist. I would extoll the virtues of APEX to anyone that would listen (mostly my wife, but she was just humoring me). By the time I left that job, 18 months later, our internal web site consisted of almost 350 pages.
At one point I read an job description something along the lines of "Developer wanted to help maintain 100 page web site with a team of 6." Six people? What? Why does it take so many people? What the hell are they using, Java?
I still consider myself an APEX evangelist, but I no longer get to work with it on a daily business. I did manage to convince my superiors though that it would be a good basic reporting tool for our data warehouse environment. We've built 2 applications so far that utilize APEX and hopefully there's more to come.