Difftastic is a structural diff tool that understands syntax. See the manual to get started, and the changelog for historical changes.
Diffing
Improved performance, particularly for line-based diffs or pathological cases (e.g. an extremely long line).
Linear diffs (used in line-based diffs and word highlighting) have changed from the Wu-Manber algorithm to the Histogram algorithm. This is a modest runtime improvement and a large improvement for memory usage in worst case scenarios.
Some diff results have slightly changed, although the diff quality should be similar. (Please file bugs if not.)
Parsing
Improved C++, Dockerfile, Haskell, JavaScript, Makefile, Perl, Ruby, Rust, Scala and TypeScript.
Improved heuristics and the default globs used for language detection.
Removed Hare support (upstream parser is no longer maintained).
Command Line Interface
--context can now be set with the short flag -c.
Release
Prebuilt binaries attached to releases now include the version in the filename.