I was recently looking through some old projects and found a screenshot of my development environment from 2006:
That's a lot of green.
The language is BlitzPlus, and the editor is Protean IDE (a custom Blitz IDE that is no longer available).
I think it's interesting to look over old screenshots like this to see how my work environment has changed (and how it's stayed the same).
Here's a shot I took during some work on beeminder.el version 1.2 this week.
One thing that stood out to me is how much visual clutter was in the old screenshot. I've removed as many toolbars and menus as possible, and try to stick to keyboard shortcuts where possible.
Current setup
I'm currently using Emacs 26.3 with the doom-nord theme. The status bar at the bottom uses doom-modeline with some slight tweaks. Font is Ubuntu Mono.
For work projects I use php-mode and web-mode. Recently I've started using lsp-mode with intelephense to add better auto-completion and documentation tooltips (which is something I'll be writing about in my book, "Developing PHP with Emacs").
I use magit for working with git repositories which has been a huge boost for efficiency. For navigating projects I use projectile with projectile-helm; they make jumping from one project to another extremely quick, which is helpful when I'm switching between client projects during the day. For project planning I use org-mode.
I'd say 80% of my professional work these days is done from within Emacs. I still use external applications like browsers and database tools, but any source code editing is done from within Emacs.
Eventually I'd like to get more comfortable using some other Emacs features like tramp (for editing files on remote servers) and EmacSQL for working with databases.
I still develop hobby projects in Blitz (using BlitzMax), although I've changed my setup a couple of times. I ended up writing blitzmax-mode so that I could write code with Emacs, and I've built a bunch of other Blitz tools over the years.