Mojibake: Low-level Unicode library in C with normalization and segmentation

What it does

Mojibake is a Unicode processing library written in C11 that handles text transformations and analysis. It implements Unicode normalization (NFC, NFD, NFKC, NFKD), case conversion, codepoint counting, segmentation, bidirectional text, collation, and confusable character detection. The entire library ships as two files: mojibake.h and mojibake.c, with no external dependencies.

Who it is for

Developers building C or C++17 applications that need to process Unicode text correctly. This includes systems software, embedded applications, and projects where pulling in large Unicode libraries is impractical. The library targets developers who want Unicode support without external dependencies or installation steps.

Pricing

The site does not show prices. Mojibake is released under the MIT License.

How it stands out

The design centers on simplicity and self-containment. Rather than requiring installation or linking against separate libraries, developers drop two files into their project. The creator explicitly built it because they disliked existing Unicode libraries. The library passes official Unicode test suites for its supported algorithms and claims to implement all Unicode standard algorithms while meeting Unicode Conformance Requirements. It targets speed and small size simultaneously, and has been tested across Linux, macOS, FreeBSD, OpenBSD, NetBSD, and Windows 11.

What a founder should check

A rival builder should verify the incumbents: what do ICU, libunistring, and other C Unicode libraries actually cost in terms of build complexity, binary size, and performance in the target use cases. Second, check what lock-in exists around existing codebases using those libraries—switching costs may be high even if Mojibake is technically superior. Third, examine whether the narrow focus on being small and self-contained creates a moat or whether competitors can copy this approach easily.

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