persistent: They exist from when they are created until they are explicitly deleted. Picos retain state based on past operations.
unique: They have an identity that is immutable. While attributes of the pico, its state, may change, its identity does not.
online: They are available on the Internet and respond to events and queries.
concurrent: They operate independently of one another and process events and queries asynchronously.
event-driven: They respond to events by changing state and sending new events.
rule-based: Their behavior is expressed as rules that pattern-match against incoming events. Put another way, rules listen for events on the pico's internal event bus.

Pico Programming Model

A collection of picos interact by sending events to or making requests of other picos in an Actor-like manner.

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While rulesets are the primary organizing feature of KRL, you cannot program KRL without understanding picos.

Picos provides a number of important services that create the execution environment for rules:

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Pico Hosting Model

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