- Async
- CD / CI
- Macros
- AWS and other Cloud services
- Advanced data structures
- Basic and advanced TCP/IP networking
- More database examples, including object databases, graph databases, BonsaiDB
- Zip files and other archives
- Authentication / authorization: OAuth2, LDAP/AD, DNS lookups
- FLTK
- GPU processing, CUDA
- Machine learning, Tensorflow
- Raft Consensus library
- Network file systems
- Statistics, math
- Crypto, SSL, SSH, other public key encryption, X.509, RusTLS
- Sound, graphics
- Games
- Search engines
- Buffer pools, garbage collection, or other reference-counted examples
- IPv6 address processing
- Cloud stuff: LB, status reporting (Vigil), routing, orchestration, containers
- Version control: libgit2: clone, change branches, create commits, push, pull
- High-performance computing: OpenMP, etc.
- Social media APIs
- Personal file sharing: OwnCloud, etc.