Removing garbage collection from the Rust language
This seems like the right decision: simplify the language, flatten the learning curve, and delegate complex functionality to libraries.But it's important to point out the general importance of good garbage collectors. GCs are importnat not only because they help avoid a common type of bugs, but because they are essential to many concurrent data structures. Performance of modern software is now (and more so in the future) largely determined not by the single-thread speed of running an algorithm, but the scalability of an algorithm as it parallelizes across cores. Many of the most scalable concurrent data structures are almost impossible to implement robustly without a really good garbage collector.As of now, the only really-good GCs are found in the JVM, and Java does indeed provide very low-level access to important memory primitives (direct control of memory fences is now possible through an undocumented API, and will be made public probably in the forthcoming Java 8). But as good and as powerful the JVM is, such algorithms will be necessary in circumstances where the JVM is not the best choice, namely embedded systems. So a garbage collector as good as those available for the JVM (or almost as good) but for a low-level systems language will be a boon.A good GC for C++ would probably be a headache because of the language's inherent unsafety in just about anything.Go is not an option in those circumstances, either. For one, while Go compiles to native binaries, the language actually operates at a higher level than Java (for example, it offers no control over thread scheduling like Java does). More importantly, choices made by the language designers might preclude a GC implementation good enough for high-performance concurrent data structures.Rust is a great language to try and build a good GC for. If it would be possible to do so in a library and not in the core language - all the better.