rudy4

https://github.com/tomash/rudy4

rudy4 lets you write Ruby native extensions in D (compiled by GDC) instead of C. This gem ships the rudy4 D library plus the `rudy4` command: `rudy4 init NAME` scaffolds a self-contained extension gem (vendoring the D sources, so it builds with no checkout), and `rudy4 doctor` checks your Ruby + GDC setup by compiling and loading a probe extension.