How to improve your macOS workstation
There are quite a few tools available to help you to get most out of your macOS workstation. Darwin, the macOS base system, is a BSD on Mach Microkernel and this gives you the possibility to use nearly all of the typical OpenSource applications written for Linux or BSD. Furthermore, a lot of Freeware for macOS is provided by various people. Lastly, you may also opt for commercial applications like MS Office or the Adobe products.
User Applications
LibreOffice
LibreOffice is a free office suite for word processing, spreadsheets, presentations, and more. It can replace Word, Excel, PowerPoint, and Access.
Microsoft Office
The Microsoft365 subscription offers access to all Microsoft Office applications (Word, Excel, PowerPoint, Outlook, ...).
PDF Reader and Writer
Apple's Preview is the standard MacOS application to view and annotate pdf files. If you want to create a PDF file you can do that without additional software using the standard print dialog. If you want you can additionally install Adobe's Acrobat Reader (proprietary, free software) or the complete Acrobat Pro application via the Adobe Creative Cloud subscription. Skim is a very powerful alternative to view and especially to annotate pdfs.
Web Browser
Aside from Apple's Safari, you can opt for any alternative web browser: Mozilla Firefox, Google Chrome
Thunderbird
Mozilla Thunderbird can be used as an alternative email client to Apple Mail.
Gimp
Gimp is a free alternative to Adobe Photoshop, allowing you to work on photos and other graphic files.
Cyberduck
Cyberduck is a front end to transfer files to and from servers, via various protocols.
LaTeX
Developer Tools and Unix Ports
Command Line Tools
The Apple Command Line Tools are required for most developer environments and can be installed with the xcode-select --install command.
Homebrew
Homebrew is a popular package management system for macOS. It provides access to command line tools as well as graphical applications (called casks).
MacPorts
MacPorts is another package management system for macOS.
MacVim
Vim is the most powerful editor of the world. MacVim is a graphical port for macOS.
Emacs
Emacs is one of the most powerful editors.
Terminal
iTerm2 is a powerful terminal emulator providing many more features than the standard macOS Terminal.