This paper will present APL Public Library management concepts used in a large in-house APL system development environment and describe a number of tools developed for this purpose. Public libraries, workspaces, functions and variables are discussed as well as documentation, reporting of changes, audit records, backup versions, and test versions. User tools discussed include functions for describing APL public files, libraries, workspaces, functions and variables, locating these objects, keyword searches, and a glossary of terms. Other user facilities include a NEWS system and an online system for submitting problem reports and requests for enhancements. Further maintenance tools include automatic generation of WSDOC listings when changes are made and automatically generated reports providing a variety of information such as libraries or workspaces lacking descriptions, lists of APL public workspaces and files with their status, function source verification, and exception reporting of workspace changes.A discussion of LOGOS, a programming environment for APL offered by IP Sharp Associates, is also presented and how it enhances the capabilities previously described.