DelphiAST is a Delphi/FreePascal Abstract Syntax Tree (AST) builder that parses Object Pascal source code into a structured XML or binary representation. The architecture centers around a core library (DelphiAST.pas) comprising a lexer/parser extension (SimpleParserEx), AST node hierarchy (DelphiAST.Classes), XML/binary serializers (Writer, Serialize.Binary), string interning pool (StringPool), and project indexing utility (ProjectIndexer). Key entry points include TPasSyntaxTreeBuilder.Run() for parsing, TProjectIndexer for dependency resolution, and demo applications like ParserDemo (GUI AST visualizer) and ProjectIndexerResearch (console project analyzer). Data flows involve source code input → lexer → parser → AST construction → serialization/output or project analysis. External dependencies include FreePascal support submodules and Delphi/FPC RTL units like Generics.Collections.