Composer is essential for modern PHP development when using packages.
Drupal has seen many changes and D8 promises to be the best version ever with views in core, big pipe, and Twig.
Symfony is a solid PHP web framework and many projects are built on top of it such as Drupal, Laravel and Lumen.
Bootstrap (Twitter) is good for speeding up front end development, and there are many options for common front-end patterns sites use.
Wordpress is fast, flexible, well supported and many developers know plug-in development for it.
For most hardware, Ubuntu is well supported, fast and good for developers.
NetBeans IDE is a good free IDE that handles many languages well with plugin support. It may not have everything other non-free IDEs have, but it is still a good choice for many.
MYSQL is a good choice for many types of database workloads and is compatible with many popular open source content management systems.
Many are using MySQL Workbench now.
MySQL Workbench has some nice options and is a go-to tool when working with MySQL. Some of the features are better than one would expect from free software.