https://www.helius.dev/blog/solana-decentralization-facts-and-figures

The Solana network is distributed across 4,514 nodes, including 1,414 validators and 3,100 RPCs (epoch 685). No single validator controls more than 3.2% of the total stake.

The Nakamoto Coefficient (NC) represents the smallest number of independent entities that can maliciously conspire to cause a liveness failure, denying the consensus needed for new block production. Solana's Nakamoto Coefficient is frequently cited as 19. The actual figure is likely lower since individual entities can permissionlessly operate multiple validators anonymously.

Solana’s validator set spans 37 countries and territories. The largest concentration is in America, with 508 validators. Four jurisdictions each hold over 10% of stake: the US with 18.3%, the Netherlands and the UK, both at 13.7%, and Germany with 13.2%.

68% of stake is delegated to European validators, with 20% delegated to North America. 50.5% of stake is delegated to validators operating within the European Union (European stake excluding Norway, Ukraine, and the UK).

The validator set is dispersed across 135 different hosting providers. The two leading providers are Teraswitch, a privately owned U.S. company hosting validators with a combined 24% of stake, and Latitude.sh (formerly Maxihost), a Brazilian-based provider of low-cost bare metal servers used by validators with a combined 19% of stake.

The Agave client codebase has 357 individual contributors. The Firedancer client, developed by a small team under the leadership of chief science officer Kevin Bowers, currently has 57 contributors.

The Jito client, a fork of the original Agave codebase that includes an out-of-protocol block space auction, currently holds a dominant 88% share of the network's stake. However, this is expected to changeconsiderably over the next twelve months as the new Firedancer client is gradually introduced and integrated into the ecosystem. Solana and Ethereum stand out as the only Layer 1 blockchains currently offering multiple client implementations.

Substantial changes to Solana’s core components undergo a formal and public Solana Improvement and Development (SIMD) proposal process. The most significant protocol-altering changes, especially those affecting economic parameters, undergo governance votes. So far, three such votes have taken place.
The Solana Foundation, established in June 2019, is a Swiss-registered non-profit organization dedicated to growing and supporting the Solana ecosystem. The SF’s relatively lean team of 60-65 full-time employees oversees funding for grants, staking programs, and developer tools.

Additionally, there is strong evidence of geographical diversity among the Solana developer community. The most recent bi-annual hackathon, Radar, drew 13,672 participants from 156 countries, with notable participation from India, Nigeria, the U.S., and Vietnam. SuperTeam, a network connecting Solana creatives, developers, and operators, has expanded to 1,300 members in 16 countries.