Download of JWasm212bw_140105.zip (JWasm212bw_140105.zip ( external link: SF.net): 400,295 bytes) will begin shortly. If not so, click link on the left.
JWasm is a Masm-compatible assembler. It supports 16-, 32- and 64-bit code, instructions up to AVX and various output formats. It's written in C.
