With .NET 5 the fastest non-PCRE C# regexredux implementation there completes in five seconds on my machine, as opposed to 8 seconds for the Java implementation

With .NET 5 the fastest non-PCRE C# regexredux implementation there completes in five seconds on my machine, as opposed to 8 seconds for the Java implementation. Still quite a bit away from C, but I'd say respectable for a purely managed implementation. It helps that the team has done a lot of optimizations for regex and other parts of the standard lib in the past few months.