How to pronounce Cap'n Proto

Cap'n Proto is most commonly pronounced "KAP uhn PROH toh" (/ˌkæpən ˈproʊtoʊ/). This pronunciation is documented by the project itself (see Hacker News — Kenton Varda (kentonv, creator) on the name origin).

Zero-copy data serialization + RPC framework by Kenton Varda, former maintainer of Google's Protocol Buffers. Per Varda himself, the name originally meant 'Capabilities and Protobufs' — NOT a Cap'n Crunch pun; he said the cereal reference 'never occurred to me,' and the 'cerealization protocol' pun was pointed out by someone else and only then added to the logo. Regardless of origin, 'Cap'n' is the ordinary contraction of 'captain', so it's said 'KAP-uhn PROH-toh' — same first word as the cereal mascot Cap'n Crunch — stress on KAP and PROH. Newcomers misread the apostrophe and say the full 'CAPtain Proto', or spell the tool name 'capnp' out as letters C-A-P-N-P. The schema file extension and compiler are 'capnp' ('cap-en-pee').

Alternate readings you might hear:

• "CAP tain PROH toh" /ˌkæpteɪn ˈproʊtoʊ/

Source: Hacker News — Kenton Varda (kentonv, creator) on the name origin

Pronouncing project and product names correctly avoids the small but persistent friction of being gently corrected during standups, conference Q&As, and team calls. Hearing the word a few times locks in the right reading better than reading IPA ever will. Pronounce is a community-maintained dictionary — every entry tagged with a confidence level and (where possible) a citable source.