Add comparison to rustPlatform and carnix

README.md

@@ -22,6 +22,24 @@ in naersk.buildPackage ./path/to/rust {}
 
 _NOTE_: `./path/to/rust/` should contain a `Cargo.lock`.
 
+## Comparison
+
+There are two other notable Rust frameworks in Nix: `rustPlatform` and
+`carnix`.
+
+`naersk` uses `cargo` directly, as opposed to `carnix` which emulates `cargo`'s
+build logic. Moreover `naersk` sources build information directly from the
+project's `Cargo.lock` which makes any code generation unnecessary.
+
+For the same reason, `naersk` does not need anything like `rustPlatform`'s
+`cargoSha256`. All crates are downloaded using the `sha256` checksums provided
+in the project's `Cargo.lock`. Because `cargo` doesn't register checksums for
+`git` dependencies, `naersk` does not support `git` dependencies.
+
+Finally `naersk` supports incremental builds by first performing a
+dependency-only build, and _then_ a build that depends on the top-level crate's
+code and configuration.
+
 
 [cargo]: https://crates.io/
 [niv]: https://github.com/nmattia/niv