When comparing Swift vs Red, the Slant community recommends Swift for most people. In the question“What is the best programming language to learn first?” Swift is ranked 32nd while Red is ranked 53rd.
Ranked in these QuestionsQuestion Ranking
Pro Modern syntax
Pro Swift is closer to other platforms
Apple’s modern programming language is easier to understand for non-iOS developers and minimizes time for additional explanations and clarifications. Moreover, Swift can be used as a script language. It is an interesting solution for the iOS community to unify writing of build scripts. At the time being iOS developers are split up in regard to this activity. Some of them write build scripts in Bash, others use Ruby, Python, etc. Swift gives an amazing opportunity to be applied to all iOS programming needs.
More details can be found here https://mlsdev.com/blog/51-7-advantages-of-using-swift-over-objective-c
Pro Works with Apple's Cocoa and Cocoa Touch frameworks
Pro Can be used as a Just-In-Time language
Pro Inherent parallelism
Pro Low memory footprint due to reference counting
Pro Backed by Apple
Pro Performance speed comparable to native C
Pro Swift has some clever tricks up its sleeve
Due to having elements of a functional programming language. Things like 'map' and 'filter' for example.
Pro Uses LLVM compiler and Obj-C runtime allowing C, Objective-C, Objective-C++ and Swift code to run side by side within a single program
Pro Simple toolchain
Other languages have complex, multi-step setups that beginners often get stuck on. Red has no installer, no setup, no dependencies*, just a single small (~1MB) command-line executable with both the compiler and repl. On Windows, you don't even have to launch executable from the command line--it has a GUI-console.
Pro Very simple syntax
Red syntax is a lot like Rebol. It's easier than most languages for beginners to pick up.
Pro Both low and high-level
Red has low enough access to do systems programming, but it's expressive enough for high-level scripting.
Pro Low cognitive load
Red has very simple syntax that's easy to learn. It gets out of your way and lets you think about the problem instead, enhancing productivity.
Con Swift is a moving target
They've released 1.2 so far, and 2.0 is coming soon. Every small update brings adjustments to paradigms (such as how to do type casting) that can be a little frustrating to absorb. Objective C was also constantly updating, however, but not at the same rate these days.
Con Not production ready
Red is still under development and not considered stable.
Con Still in beta
It mostly works. It's good enough for building usable applications, but some planned features are missing.