The most significant change in version 5.1 is a rewrite of the GUI library. Unix/X users will see the biggest difference with this change, because DrRacket and all Racket GUI programs now take on the desktop theme for menus, buttons, and other GUI widgets.
In the long run, Racket GUI programs on all platforms will improve as a result of the library rewrite. In the short run, beware that this first release of a new library will inevitably include a new set of bugs.
Version 5.1 changes in more detail:
- The racket/draw library—which implements the drawing half the GUI toolkit—can be used independent of the racket/gui/base library and without a graphics display (e.g., without an X11 connection).
The new library has one small incompatibility with the old GUI toolbox: 'xor drawing is no longer supported. The new library has many additional features: rotation and general affine transformations, PDF and SVG drawing contexts, gradients, and alpha-channel bitmaps.
- The GRacket executable is no longer strictly necessary for running GUI programs, because the racket/gui/base library can be used from Racket. To the degree that a platform distinguishes GUI and console applications, however, the GRacket executable still offers some additional GUI-specific functionality (e.g., single-instance support).
The new racket/gui/base library includes small incompatibilities with the old GUI toolbox: the send-event, current-ps-afm-file-paths, and current-ps-cmap-file-paths functions have been removed. The racket/gui/base library re-exports racket/draw, so it includes the same drawing functionality as before (except for 'xor drawing).
- The new racket/snip library can be used independently of racket/gui/base to work with graphical editor content (e.g., images in student programs). Like racket/draw, the racket/snip library is re-exported by racket/gui/base.
- The Web Server includes a backwards incompatible change that prevents X-expressions and lists of bytes from being directly returned from servlets. This change will increase performance for those types of responses and allow easier experimentation with response types. Please see "collects/web-server/compat/0/README" in the installation to learn about porting your servlets forward. Don't worry. It's easy.
- The new raco demodularize tool collapses a module's dependencies into a single module comprising the whole program. This transformation currently provides no performance improvement, but is the basis for cross-module optimization and dead-code elimination tools to come. The transformation is currently useful for static analysis of whole Racket programs.
- The picturing-programs teachpack, formerly installed via PLaneT, is now bundled with the standard distribution. Use the teachpack with (require picturing-programs) instead of (require installed-teachpacks/picturing-programs). The old PLaneT-based installation procedure still works, but it now merely installs a stub that invokes the bundled version.
- Slideshow picts, racket/draw bitmaps, and images created with 2htdp/image can now be used directly in Scribble documents. More generally, the new file/convertible protocol enables any value that is convertible to a PNG and/or PDF stream to be used as an image in a Scribble document.
- The Same game sports a new look and an improved scoring system. (The current known high score is 12,429; can you beat that?)