10 projects are written in C++, listed alphabetically. They are ArangoDB, Ceph, ClickHouse, DuckDB, Envoy, KeyDB, MongoDB, Nift, Swoole and Typesense. Mostly databases and caches, servers and proxies and site and docs generators, of 5 categories in all. 38 records do not record this field, and cannot appear here either way. Counts only projects with momentum; the full list has the rest.
A
ArangoDBMulti-model database for documents, graphs and key-value data, queried with the AQL query language.
C
CephOpen-source distributed storage system that serves object, block and file interfaces from one cluster built on commodity hardware.
ClickHouseColumn-oriented SQL database management system for analytical queries, available as open-source server software and as a cloud service.
D
DuckDBAnalytical SQL database that runs in-process inside Python, Node.js and other applications, with a WebAssembly build for browsers.
E
EnvoyOpen source edge and service proxy for cloud-native applications.
K
- KeyDB
Multithreaded, Redis-compatible key-value database and cache server, a fork of Redis.
M
MongoDBDocument database server built on the document model, offered as a community edition and as commercial Enterprise editions.
N
NiftDependency-aware command-line build tool and template language that generates websites from HTML, content and data files.
S
SwooleCoroutine-based PHP extension for concurrent networking and TCP, UDP, Unix socket, HTTP and WebSocket servers.
T
TypesenseOpen-source search server with an HTTP API that indexes collections of documents for instant search, self-hosted or as Typesense Cloud.
What is the best web software written in C++?
We don't know. A portfolio, a shop and a documentation site need different things from their software, and so does a team of one against an agency. Nobody pays to be listed here and the order is alphabetical.