Developer Venus has released version 5 of its opinionated Perl 5 library, providing a cohesive set of modern primitives for data modeling, validation, and error handling. This major update includes intentional breaking changes to clean up long-standing design constraints, aiming to give developers stronger structure without abandoning Perl idioms.

The release introduces first-class support for private instance data, a thoroughly documented type system, and new core utilities like Venus::Map, Venus::Set, and Venus::Result. It also overhauls error handling with Venus::Error and Venus::Try, expands validation options, and refactors the dependency injection container and factory model for cleaner extension.

Alongside the core library, the project includes two companion repositories: bye for example-driven learning and cfu for Claude Code instructions. The update also brings a more capable CLI framework with routing and spec-driven configuration, better .env file support, and an overhauled test suite. This release aims to spark discussion on what "modern Perl" can look like today.