solana-signer is used at run time in 338 crates (of which 27 optionally). It is a direct run-time dependency in 47 crates. It's used only as a dev dependency in 28 crates (of which 3 directly).

Depender (with downloads and own rev deps) solana-signer version
241K 8 solana-zk-token-sdk ^2.2.1
162K 47 solana-rpc-client-api =2.2.1
156K 11 solana-quic-client =2.2.1
157K 3 solana-thin-client =2.2.1
156K 14 solana-tpu-client =2.2.1
156K 276 solana-client =2.2.1
156K 28 solana-streamer =2.2.1
145K 13 solana-zk-sdk ^2.2.1
141K 38 solana-vote-program =2.2.1
339K 654 solana-sdk optional ^2.2.1
110K 47 solana-clap-utils ^2.2.1
110K 28 solana-remote-wallet ^2.2.1
102K 54 solana-keypair ^2.2.1
98K 5 solana-client-traits ^2.2.1
98K 4 solana-genesis-config ^2.2.1
96K 5 solana-presigner ^2.2.1
96K 3 solana-offchain-message ^2.2.1
95K 12 solana-system-transaction ^2.2.1
158K 24 solana-perf optional =2.2.1
40K 9 solana-faucet =2.2.1
37K 5 solana-tls-utils ^2.2.1
104K 44 solana-transaction optional ^2.2.1
16K 11 solana-clap-v3-utils =2.2.1
6.2K 3 litesvm ^2.2
1.3K 3 solana-cli =2.2.1
1.0K 1 solana-tps-client =2.2.1
850 solana-keygen =2.2.1
440 agave-cargo-registry =2.2.1
380 agave-install =2.2.1
240 litesvm-token ^2.2
210 1 surfpool-core ^2.2.1
litesvm-loader ^2.2
554K 83 spl-token-2022 dev ^2.2.1
183K 15 solana-config-program dev =2.2.1
162K 56 solana-rpc-client dev =2.2.1
156K 3 solana-rpc-client-nonce-utils dev =2.2.1
120K 7 solana-vote dev =2.2.1
102K 7 solana-ed25519-program dev ^2.2.1
101K 7 solana-secp256k1-program dev ^2.2.1
35K 5 solana-cost-model dev =2.2.1
27K 8 solana-svm dev =2.2.1
27K 3 agave-transaction-view dev ^2.2.1
26K 10 solana-runtime-transaction dev =2.2.1
18K 6 solana-compute-budget-instruction dev =2.2.1
18K 27 solana-cli-output dev =2.2.1
13K 17 solana-entry dev =2.2.1
10K 6 solana-poh dev =2.2.1
8.4K 1 solana-wen-restart dev =2.2.1
340 solana-tpu-client-next dev =2.2.1
160 solana-accountgen dev ^2.2.1