Blockchains running code.
WHAT THEY ADDED
The ability to deploy programs that execute according to the network's rules.
WHAT THAT ENABLES
Assets issued by anyone Automated agreements Applications with no operator
WHAT A VIRTUAL MACHINE IS HERE
The environment executing those programs identically on every node.
WHY IDENTICAL EXECUTION MATTERS
Consensus requires every node reaching the same result.
WHAT THAT PROHIBITS
Randomness External data access Anything producing different results per node
WHAT PROGRAMS COST TO RUN
A fee proportional to computation and storage used.
WHY
Otherwise a program could consume the network's resources indefinitely.
WHAT ACCOUNT TYPES EXIST
Controlled by a key Controlled by code
WHAT THE SECOND MEANS
An account whose behaviour is defined by a deployed program.
WHAT COMPOSABILITY MEANS
Programs calling each other freely.
WHAT IT ENABLES
Applications built from others, without permission.
WHAT IT RISKS
A defect in one propagating into everything depending on it.
WHAT THE MAJOR NETWORKS DIFFER IN
Throughput, cost, finality, programming language, and the size of their ecosystems.
WHAT TO ASSESS
Which is appropriate, rather than which is popular.
