Features

PXX is a small native compiler with a direct frontend-to-ELF pipeline.

Compiler

Self-hosting Pascal compiler.
Direct ELF executable output: no assembler or linker subprocess for normal Pascal programs.
Alternate output modes for interop with other toolchains: --emit-obj writes a relocatable .o on any target; --shared writes an x86-64 .so (currently validated via the .asm assembly-source frontend).
Zero-dependency binaries by default: no libc, no DT_NEEDED, only Linux kernel syscalls at runtime — for every frontend, not just C. Linking a system shared library is opt-in and the only thing that adds a dependency; the alternative is compiling that library's source in, which keeps the binary self-contained.
Cross-language imports with no wrapper layer: frontends share one backend, symbol table, and import resolver, so import/uses resolves a C header, a Pascal unit, or a Nil Python module through the same chain — no FFI blocks, IDL, or generated bindings. See Cross languages.
Byte-identical fixedpoint builds are part of the development gate.
DWARF debug info with -g on Linux targets.

Object Pascal dialect with classes, interfaces, generics, overloads, operators, exceptions, RTTI, managed strings, dynamic arrays, and properties (including indexed and default).
Interfaces in both models: COM (reference-counted, the default) and CORBA (unmanaged, {$interfaces corba}).
Advanced records (methods, constructors, class operator overloads), metaclasses (class of), and class properties / class vars.
Opt-in FPC-parity runtime checks per region: range ({$R+}), overflow ({$Q+}), and IO ({$I+}); plus opt-in strictness flags (--strict-visibility, --strict-case, …). Lax by default.
Conditional compilation and a PXX identity symbol.
Concurrency on two axes: a single-thread cooperative coroutine scheduler, plus real OS threads (TThread) and a data-parallel parallel for loop over a libc-free worker pool (build threaded code with --threadsafe).
Inline assembly and an assembly-source (.asm) frontend are available, but should be treated as advanced or unstable surfaces.
Alternate high-level frontends: a C frontend (C99-class, passes the full c-testsuite conformance battery, and compiles real corpora such as SQLite, Lua, zlib, and tcc) and Nil Python, a statically-typed Python-shaped dialect. Both are mainline, gated frontends, not experiments — see compatibility status.

PXX is experimental. Do not use generated programs for production, security sensitive, safety sensitive, or public network-facing workloads.