query plan caching (sql server)

Is there a measure of time frame as to which the execution plan of inline queries will cached?

There is an algorithm (will find it), but practically it will stay there:

• while being used (Edit: See AdaTheDev's answer)

• until statistics update (also implied by index rebuild)

• until definition changes (including whitespace and case)

• SQL instance restart

• until severe memory pressure

SQL Server 2008 article

StackExchange Database Administrators Q#11701, answer score: 6