Currently retired, I used to write software for medical-based applications. My professional career primarily involved programming in C/C++, Smalltalk, Java, and Python.

Writing Python programs with a well-customized Emacs editor was one of the joys of my daily life.

Open source technologies that really moved the needle for me during my career:

• GNU/Linux and the GNU toolchain
• Django
• Boto (AWS)
• git & mercurial
• PostgreSQL
• Salt (configuration management)
• Various VMs in general and their subsystems

It's easy to take these for granted, but none of these tools were available during the first decade of my professional career (or two decades, if you include my early unpaid coding in BASIC, Assembly, FORTRAN and COBOL.