Until leaving Oracle about a year ago, I'd been doing a lot of development in PL/SQL, which is extremely similar and compiles to the same ADA bytecode (called D

Until leaving Oracle about a year ago, I'd been doing a lot of development in PL/SQL, which is extremely similar and compiles to the same ADA bytecode (called DIANA). Most of Oracle's E-Business Suite is written in PL/SQL, although some components are being re-written in Java (ADF) in the new Fusion Middleware stack. If your company is using Oracle for payroll or financials (this includes lots of companies, including Apple, Google etc), it's likely some of the customizations have been developed recently, and they've been developed in PL/SQL. Many of the components in EBS have not changed in decades So to answer your question, developers at Google right now are writing in Ada (well almost): > https://www.google.com/about/careers/search/?#!t=jo&jid=1144001& https://www.google.com/about/careers/search/?#!t=jo&jid=1144... It's not easy to rewrite either. Writing ERP software is extremely hard, because it can't be cleanly modeled in a few abstractions. There are a lot of edge cases. I would suggest reading Ward Cunningham's http://c2.com/cgi/wiki?WhyIsPayrollHard http://c2.com/cgi/wiki?WhyIsPayrollHard