frum vs FVM

frum is a free Ruby version manager written in Rust. It can install and uninstall Ruby versions, list available or installed versions, and select a global or local version. It also works with .ruby-version files, so projects can specify which Ruby version frum should use. The project describes its implementation as pure Rust and says it does not use ruby-build. Installation methods listed include Homebrew or Linuxbrew, Arch Linux packages, Cargo, and release binaries. The README provides setup instructions for Bash, Zsh, and Fish and lists shell auto-completion. Ruby installation accepts configuration options such as an OpenSSL directory and jemalloc allocator selection. The README reports a benchmark in which evaluating frum init ran about six times faster than evaluating rbenv init. The project is MIT licensed and welcomes contributions, issues, and pull requests. Linux and macOS are listed as supported platforms; Windows is mentioned in the project’s goals. Its latest listed release is v0.1.2.

FVM manages Flutter SDK versions by project, allowing teams to keep builds consistent while using different versions across projects. A project’s `.fvmrc` file records its selected Flutter version and can include project-specific settings and flavors. FVM switches among installed SDKs without downloading them again. It can identify unreferenced versions, preview cleanup candidates, and remove unused SDKs with `fvm cleanup`. The documentation describes commands suitable for CI/CD automation and support for custom Flutter repositories. FVM provides packages for macOS, Linux, and Windows, with architecture availability varying by system. Installation options include a shell script, Homebrew, Chocolatey, Pub, and standalone packages. FVM detects VS Code and updates `.vscode/settings.json` for the Dart Code extension to use the project’s managed SDK. Android Studio and IntelliJ settings must be configured separately to point to the FVM SDK path. JSON API commands expose installed SDKs, releases, cleanup data, environment context, and project configuration. FVM stores known project roots in a machine-local file and says it does not scan disks for projects. The project is licensed under MIT.