Lazarus 4 is the latest version of the all-FOSS but Delphi-compatible IDE for the FreePascal compiler.

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The IDE is developed independently from the underlying Pascal language that it’s written in, so this doesn’t mean a whole new version of FreePascal: Lazarus 4 was built with FreePascal 3.2.2 which was released in 2021. It replaces Lazarus 3.8, which was the current version when we talked about it for Delphi’s 30th anniversary back in February.

Lazarus somehow manages to feel Windows-like even on a Mac, but it works – click to enlarge
Version 4 comes along relatively soon after the last new major version, Lazarus 3.0 which came out in December 2023. The project’s Gitlab page has a long list of issues fixed in this release. The version 4.0 release notes have a complete list of changes and new features. There are substantial changes in its various events and classes. Perhaps the most immediately visible change will be how the IDE handles docking:
It’s a multi-platform IDE, and the Sourceforge page has packages for both 32-bit and 64-bit Windows, Linux, and FreeBSD. On Apple hardware, it offers PowerPC, x86 and Arm64 versions; Cocoa development needs macOS 12 or higher, but using the older Carbon APIs it supports OS X 10.5 to 10.14. There’s also a Raspberry Pi version for the Pi 4 and later. It supports a wide variety of toolkits for GUI programming, as the project wiki shows: Win32, Gtk2 and work-in-progress Gtk3, and Qt versions 4, 5 and 6, among others.
One criticism we’ve seen of the FreePascal project in general concerns its documentation, although there is quite a lot of it: eight FPC manuals, and lengthy Lazarus docs in multiple languages. There is a paid-for tutorial e-book available, too.
Something which might help newcomers to the language here is a new e-book: FreePascal From Square One by Jeff Duntermann. The author says:
He does have a caveat, though:
There are other free resources out there, such as this course in Modern Pascal. The more, the merrier, though.
Pascal isn’t cool or trendy any more, but even so, it remains in the top ten on the TIOBE index. Perhaps these new releases will help it to rise up the ratings a little more. ®