Glimmer DSL for SWT (JRuby Desktop Development Cross-Platform Native GUI Framework) is a native-GUI cross-platform desktop development library written in JRuby, an OS-threaded faster JVM version of Ruby. It includes SWT 4.30 (released on December 1, 2023). Glimmer's main innovation is a declarative Ruby DSL that enables productive and efficient authoring of professional-grade desktop applications by relying on the robust Eclipse SWT library, with the familiar native look, feel, and behavior of GUI on Mac, Windows, and Linux. Glimmer additionally innovates by having built-in data-binding support, which greatly facilitates synchronizing the GUI with domain models, thus achieving true decoupling of object oriented components and enabling developers to solve business problems (test-first) without worrying about GUI concerns, or alternatively drive development GUI-first, and then write clean business models (test-first) afterwards. Not only does Glimmer provide a large set of GUI widgets, but it also supports drawing Canvas Graphics like Shapes and Animations. To get started quickly, Glimmer offers scaffolding options for Apps, Gems, and Custom Widgets. Glimmer also includes native-executable packaging support, sorely lacking in other libraries, thus enabling the delivery of desktop apps written in Ruby as truly native DMG/PKG/APP files on the Mac, MSI/EXE files on Windows, and DEB/RPM files on Linux. Glimmer was the first Ruby gem to bring SWT (Standard Widget Toolkit) to Ruby, thanks to creator Andy Maleh, EclipseCon/EclipseWorld/RubyConf speaker. If you liked Shoes, You'll love Glimmer!