BPF (Berkeley Packet Filter)

Berkeley Packet Filter—the original bytecode format used for Solana programs, inherited from Linux's eBPF. Programs written in Rust or C are compiled to BPF bytecode and executed in a sandboxed VM. BPF has been superseded by SBF on Solana but the tooling names (BPF Loader, cargo build-bpf) persist for historical reasons.