When comparing DM vs Rebol, the Slant community recommends Rebol for most people. In the question“What is the best programming language to learn first?” Rebol is ranked 46th while DM is ranked 59th. The most important reason people chose Rebol is:
Almost natural language, for example: `write %out.html read http://google.com`.
Ranked in these QuestionsQuestion Ranking
Pro Active development
DM and BYOND are constantly being developed and expanded, with feedback from the community, and Lummox as the lead developer.
Pro Active community
The BYOND community is helpful, and has been active for decades, so there are many solutions available. You can find many answers in the forums.
Pro Excellent documentation
Documentation is easy to learn, and can be found here.
Pro Quickly create online multiplayer games
Makes networking easy, so you can just make your game.
Pro Easy to learn
One of the easiest to learn languages. Similar to Python and C++.
Pro Human friendly
Almost natural language, for example:
write %out.html read http://google.com.
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 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 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 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.
Con Proprietary language
DM is owned and developed by BYOND. As such, you will only be able to use it for software created using BYOND's software suite.
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.
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.