Spire is a crypto startup focused on Ethereum scaling, developing the "Based Stack," a rollup framework designed to enable builders to deploy application-specific chains, known as appchains. The Based Stack emphasizes "Based Sequencing," which allows app developers to use Ethereum Layer 1 as the sequencing layer instead of relying on centralized sequencers. This approach maintains the network effects of the Ethereum Layer 1 blockchain and provides benefits such as L1 composability, credible neutrality, liveness, censorship resistance, and decentralization. Additionally, the Based Stack enables Maximal Extractable Value (MEV) internalization, allowing appchains to capture the MEV they generate, which traditionally would go to sequencers.