The Curl language has been designed so that user interface layouts can be described declaratively and concisely when directly writing Curl code. Features such as keyword arguments and elastics, as well as built-in layout components such as Table, HBox, VBox, and Grid, all contribute to this property. Therefore, experienced Curl developers often find that they can specify a user interface as fast, or faster, by writing Curl source code directly, than by using the VLE. This is particularly true if the user interface has many dynamic, data-dependent components: for example, a Table where the number of rows or columns could vary dynamically depending on a user's data. In the case of many other languages, specifying user interfaces requires writing much larger amounts of repetitive code, so the advantages of using a visual editor are greater in those languages.

That being said, there are several situations in which the VLE is a valuable tool for Curl development:

1. When you are specifying static layouts such as dialog boxes, the VLE lets you see right away how your dialog box will look, and how its look will be affected by options you specify. We encourage the use of VBox, HBox, and Table even when using the VLE to design dialog boxes, but if your design is based on placing objects at absolute (x,y) positions in a Canvas, then the advantages of using the VLE are even greater.
2. When the look of a GUI layout will be modified by a designer who is not an experienced Curl coder, using the VLE to create the initial layout will allow the designer later on to use the VLE for modifying the layout without actually having to get into the Curl code.
3. If you are not an experienced Curl coder, you may be able to work more efficiently using the VLE because you can instantly see the effects of specifying different options, without even having to save and run the applet.

In many cases, it will make sense to use the VLE to design some parts of an application's user interface and specify other parts of the interface in Curl code. For example, many of the dialog boxes in the VLE itself were built using the VLE for reason (1) above, but the layout of the main VLE window is not specified using the VLE because it includes many dynamic elements that depend on the actual layout being edited, as well as on user choices such as whether the various VLE panes are exposed or hidden.