1401. group-by
      Group-by is a Common Lisp library to help group data into trees (of various formats) based on common/shared values
1402. GRT Raytracer
      GRT Raytracer is a Common Lisp ray-tracing system
1403. Gsharp
      Gsharp is a graphical, interactive score editing application for standard Music notation
1404. GSLL
      GNU Scientific Library for Lisp allows you to use the GNU Scientific Library (GSL) from Common Lisp
1405. Gsoc
      Google Summer of Code
1406. GSoC 2011 Parenscript project page
      Project ideas for the Parenscript GSoC 2011 mentoring organization
1407. gtfl
      GTFL is a graphical terminal for Common Lisp
1408. Gtk
      Gtk (GTK+) is a Graphics Toolkit written in C, primarily developed for use with the X Window System
1409. GTK binding
      This page lists Common Lisp bindings for the GTK GUI toolkit
1410. gtk-cffi
      GTK-CFFI is a Common Lisp GUI library, that provides concise and idiomatic syntax to use GTK+ library (for now GTK+ 3.0)

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