Steel Bank Common Lisp version 2.6.7

Steel Bank Common Lisp (SBCL) version 2.6.7 was released on July 28, 2026, introducing a new SB-MANUAL contrib module that embeds the SBCL manual in docstrings for interactive exploration and browsing. The release also adds DOCUMENTATION support for declaration doc-types and expands platform support with ARM64 SIMD capabilities and AVX512 instruction support on X86-64 processors.