Lisp to C Migration

Lisp systems often contain valuable domain logic, symbolic processing, rule engines, and long-lived business applications. Zwiegnet provides Lisp to C migration services to evaluate legacy Lisp code and move appropriate components into maintainable C where native integration, deployment constraints, or performance requirements justify the change.

Lisp's dynamic data model, garbage collection, macros, and runtime semantics do not map directly to C. We identify those differences early and recommend a migration boundary that avoids an unnecessary or risky rewrite.

Our migration process includes:

• Dialect and Runtime Assessment – Identify Common Lisp, Scheme, or other Lisp dialects, implementations, libraries, macros, and runtime assumptions.
• Application Behavior Mapping – Document core functions, data flows, dynamic features, evaluation behavior, and external interfaces.
• Data Model Design – Plan C representations for lists, symbols, trees, hash tables, dynamic values, and other structures used by the application.
• Memory Management Strategy – Determine how garbage-collected object lifetimes and dynamic allocation should be represented safely in C.
• Macro and Language Feature Review – Identify macro-heavy or reflective code that requires redesign rather than mechanical translation.
• Selective Native Conversion – Prioritize stable algorithms, compute-intensive routines, and integration components that benefit from C while retaining Lisp where it remains advantageous.
• API and System Integration – Define clear interfaces for existing services, libraries, files, and operating-system calls.
• Behavioral and Regression Testing – Verify results, edge cases, data handling, and error behavior against the original application.
• Build, Profiling, and Documentation – Validate GCC/Clang builds, benchmark the relevant workloads, and document architecture and maintenance decisions.

For some systems, a hybrid Lisp-and-C architecture or compiler-assisted approach may be more reliable and cost-effective than translating every expression into C.

Located between Madison and Milwaukee, Wisconsin since 2009 — direct, personal service focused on practical systems engineering.