Implement hot code reloading so that the Prizm application can be modified while its running

[okmatija]

Implementing hot code reloading is a high priority feature and should make Prizm's scripting workflow quite similar to the runtime scripting features available in other tools because you will be able to add console commands without restarting Prizm

Alternatively implement a way to save/load program state? This option would help for cases when we want to revisit a debugging session much later on... Probably we want both of these things, but hot code reloading seems more important.