When comparing LiveCode vs Rebol, the Slant community recommends LiveCode for most people. In the question“What is the best programming language to learn first?” LiveCode is ranked 35th while Rebol is ranked 51st.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Fast to get results
Pro Cross-platform
Inside LiveCode's IDE you can build for OSX, Linux and Windows, and (making use of Xcode and the Android SDK) for iOS and Android too
Pro Extremely simple to get started
Single-click install of entire development environment, and all-in-one IDE makes it easy to go from visually layout out a user interface to writing code to power it to creating your own single-file applications.
Pro GUI-driven development
In LiveCode, you start by dropping GUI elements into place, then add the code that makes them function. This lets beginners see visual results right away, which is often more exciting (especially for young students). It also lets you focus on the user interaction before you get into the nitty-gritty of code implementation.
Pro Approachable yet capable language
Pro Highest ROI compared to other popular cross-platform development tools
Fluid production - from prototyping to delivery in one toolkit. With a high-level language that includes GUI controls as native elements, code more directly expresses the end-user experience. And the platform coverage is awesome, nearly unmatched.
Pro Very simple syntax
Rebol's name came from "Relative Expression Based Object Language". Rebol is a functional language and everything is an expression that returns a value. Things that have to be baked into the grammar in other languages are simple function calls with block arguments in Rebol.
Pro Homoiconic
Code is data, and data can be code. Rebol is based on a simple block data structure, used both for data and for the code itself. Blocks can be manipulated programmatically, and then evaluated as code. This makes metaprogramming easy in Rebol.
Pro Human friendly
Almost natural language, for example: write %out.html read http://google.com
.
Pro Graphical user interface
Beginners are usually stuck making command-line applications in other languages, because GUIs are too hard. Rebol GUIs are easy enough to start with.
Pro Domain specific languages
Rebol's simple homoiconic syntax makes it easy to create "Rebol dialects"--domain-specific languages optimized for a particular purpose. The Rebol distribution includes many of these, and users are free to create more. These DSLs make tasks that would be complicated to express in other languages easy.
Cons
Con fringe use
Con Poor ecosystem
Not a mainstream programming language.
Con Not (yet?) Free Software
Rebol 2's core is free (gratis) for commercial use, but the license prohibits modification, a violation of the DFSG. Rebol 3 is Free Software (Apache 2.0), but isn't production ready.
Con Very niche language
Small community.
Con No separators
A function call expression has no parentheses, and there are no separators between sequenced expressions, not even newlines. This means that you have to know the arity of every function in an expression to know how to parse it. It also means you can run into subtle, hard-to-find bugs if you don't provide enough arguments, since the result of the next expression will be passed instead.