With the introduction of the LotusScript language and integrated development environment (IDE) in Release 4.0, the range of Notes application types that could be developed was greatly expanded. Thanks to a set of triggering events onto which developers could “hang” LotusScript programs and thanks to a set of Notes objects that appear in LotusScript as native classes, application developers could begin to make Notes do things that once were difficult or impossible. Now, with Notes Release 4.5, even more is possible. In fact, there are so many new LotusScript features and enhancements that it takes a two-part article to cover them all. This is the first installment. It introduces the new front-end and back-end LotusScript classes and the new “Script Library” feature, which allows designers to store reusable subroutines and functions at the database level for use in any or all forms. It also points designers in the direction of how to use these new features.