tl;dr: SBCL 2.6.7 has been released, adding a new SB-MANUAL contrib module that embeds the manual in docstrings for interactive exploration, plus AVX512 support on x86-64 and SB-SIMD support on ARM64. The release includes multiple bug fixes (miscompilation of MULTIPLE-VALUE-CALL, NaN handling in LOG, EQL complex types) and optimizations for UTF-8 SIMD conversions, COUNT transforms, and constant complex number passing. Documentation was migrated to a Markdown-conforming internal format while still generating Texinfo output.