The VLE (Visual Layout Editor) is adequate. The online help (Curl Documentation Viewer) is an outstanding resource. With the IDE installed the online examples in the help are 'live' output from code that can be edited, restored and saved as an applet. This feature is usually only found in an advanced IDE such as Smalltalk.
The VLE is an interesting place to start: the source code for the VLE is installed as part of the IDE installation - it is written in Curl and constitututes a very large example.
There is a java-type packaging system that encourages modular software. Imported packages are usually a part of compilation (on the fly) and code reuse.
Curl provides an OCC (Occasionally Connected Computing) set of features for applications which can also run when not connected to the Internet: this includes client-side persistent data and local protected storage for each user of a web application.
One of the web GUI challenges is 'stretchy' widgets provided in Curl by using make-elastic. This is a feature required in most RIA applications.