This book is a collection of notes and sample codes written by the author while he was learning WSDL himself. Topics include introduction to WSDL (Web Services Definition Language); WSDL document structure; 'types', 'interface', 'binding' and 'service' definition elements; differences between style='rpc' and style='document'; using WSDL document with SoapUI; parsing WSDL documents with Python, PHP, Perl, and Java programs. Updated in 2024 (Version v2.22) with Python tutorials. For latest updates and free sample chapters, visit https://www.herongyang.com/WSDL.