solana/book/src/introduction.md

# What is Solana?

Solana is an open source project implementing a new,
high-performance, permissionless blockchain. Solana is also the name of a
company headquartered in San Francisco that maintains the open source project.

# About this Book

This book describes the Solana open source project, a blockchain built from the
ground up for scale. The book covers why Solana is useful, how to use it, how it
works, and why it will continue to work long after the company Solana closes
its doors. The goal of the Solana architecture is to demonstrate there exists a
set of software algorithms that when used in combination to implement a
blockchain, removes software as a performance bottleneck, allowing transaction
throughput to scale proportionally with network bandwidth. The architecture
goes on to satisfy all three desirable properties of a proper blockchain: 
it is scalable, secure and decentralized.

The architecture describes a theoretical upper bound of 710 thousand
transactions per second (tps) on a standard gigabit network and 28.4 million
tps on 40 gigabit. Furthermore, the architecture supports safe, concurrent
execution of programs authored in general purpose programming languages such as
C or Rust.

# Disclaimer

All claims, content, designs, algorithms, estimates, roadmaps, specifications,
and performance measurements described in this project are done with the
author's best effort. It is up to the reader to check and validate their
accuracy and truthfulness. Furthermore, nothing in this project constitutes a
solicitation for investment.

# History of the Solana Codebase

In November of 2017, Anatoly Yakovenko published a whitepaper describing Proof
of History, a technique for keeping time between computers that do not trust
one another. From Anatoly's previous experience designing distributed systems
at Qualcomm, Mesosphere and Dropbox, he knew that a reliable clock makes
network synchronization very simple. When synchronization is simple the
resulting network can be blazing fast, bound only by network bandwidth.

Anatoly watched as blockchain systems without clocks, such as Bitcoin and
Ethereum, struggled to scale beyond 15 transactions per second worldwide when
centralized payment systems such as Visa required peaks of 65,000 tps. Without a
clock, it was clear they'd never graduate to being the global payment system or
global supercomputer most had dreamed them to be. When Anatoly solved the problem of
getting computers that don’t trust each other to agree on time, he knew he had
the key to bring 40 years of distributed systems research to the world of
blockchain. The resulting cluster wouldn't be just 10 times faster, or a 100
times, or a 1,000 times, but 10,000 times faster, right out of the gate!

Anatoly's implementation began in a private codebase and was implemented in the
C programming language. Greg Fitzgerald, who had previously worked with Anatoly
at semiconductor giant Qualcomm Incorporated, encouraged him to reimplement the
project in the Rust programming language. Greg had worked on the LLVM compiler
infrastructure, which underlies both the Clang C/C++ compiler as well as the
Rust compiler. Greg claimed that the language's safety guarantees would improve
software productivity and that its lack of a garbage collector would allow
programs to perform as well as those written in C.  Anatoly gave it a shot and
just two weeks later, had migrated his entire codebase to Rust. Sold.  With
plans to weave all the world's transactions together on a single, scalable
blockchain, Anatoly called the project Loom.

On February 13th of 2018, Greg began prototyping the first open source
implementation of Anatoly's whitepaper. The project was published to GitHub
under the name Silk in the loomprotocol organization. On February 28th, Greg
made his first release, demonstrating 10 thousand signed transactions could be
verified and processed in just over half a second. Shortly after, another
former Qualcomm cohort, Stephen Akridge, demonstrated throughput could be
massively improved by offloading signature verification to graphics processors.
Anatoly recruited Greg, Stephen and three others to co-found a company, then
called Loom.

Around the same time, Ethereum-based project Loom Network sprung up and many
people were confused about whether they were the same project. The Loom team decided it
would rebrand. They chose the name Solana, a nod to a small beach town North of
San Diego called Solana Beach, where Anatoly, Greg and Stephen lived and surfed
for three years when they worked for Qualcomm. On March 28th, the team created
the Solana Labs GitHub organization and renamed Greg's prototype Silk to
Solana.

In June of 2018, the team scaled up the technology to run on cloud-based
networks and on July 19th, published a 50-node, permissioned, public testnet
consistently supporting bursts of 250,000 transactions per second. In a later release in 
December, called v0.10 Pillbox, the team published a permissioned testnet
running 150 nodes on a gigabit network and demonstrated soak tests processing
an *average* of 200 thousand transactions per second with bursts over 500
thousand. The project was also extended to support on-chain programs written in
the C programming language and run concurrently in a safe execution environment
called BPF. 

# What is a Solana Cluster?

A cluster is a set of computers that work together and can be viewed from the
outside as a single system. A Solana cluster is a set of independently owned
computers working together (and sometimes against each other) to verify the
output of untrusted, user-submitted programs. A Solana cluster can be utilized
any time a user wants to preserve an immutable record of events in time or
programmatic interpretations of those events. One use is to track which of the
computers did meaningful work to keep the cluster running. Another use might be
to track the possession of real-world assets. In each case, the cluster
produces a record of events called the ledger. It will be preserved for the
lifetime of the cluster. As long as someone somewhere in the world maintains a
copy of the ledger, the output of its programs (which may contain a record of
who possesses what) will forever be reproducible, independent of the
organization that launched it.

# What are Sols?

A sol is the name of Solana's native token, which can be passed to nodes in a
Solana cluster in exchange for running an on-chain program or validating its
output. The system may perform micropayments of fractional sols and a sol
may be split as many as 34 times. The fractional sol is called a *lamport*. It
is named in honor of Solana's biggest technical influence, [Leslie
Lamport](https://en.wikipedia.org/wiki/Leslie_Lamport). A lamport has a value
of approximately 0.0000000000582 sol (2^-34).