GGUF
The single-file model format used by llama.cpp, carrying weights plus all metadata needed to run them.
GGUF replaced GGML as llama.cpp's container. A file begins with a header: a magic number, version, tensor count, a key-value metadata block, then one record per tensor giving its name, dimensions and quantization type.
Because the header is self-delimiting and sits at the start of the file, it can be read with a single HTTP range request without downloading the weights — which is how this site inspects quantizations it has never downloaded. Headers run from around 54 KB to 13 MB, the large ones because tokenizer vocabularies are stored inline.