The article introduces LEDA, a comprehensive library for combinatorial and geometric computing, which aims to address the lack of a standard library in this area. Combinatorial and geometric computing, a core area of computer science, deals with data structures and algorithms for objects like graphs, sequences, points, lines, and convex hulls. The absence of a standardized library has hindered the impact of these areas on broader computer science applications. LEDA provides a wide range of data types and algorithms, including stacks, queues, lists, dictionaries, graphs, and geometric structures, along with precise specifications and efficient implementations. It supports parameterized data types and offers multiple implementations for many data structures, allowing users to choose the most suitable one. LEDA also includes a novel "item" concept to enhance efficiency in data structures. The article highlights four examples: a word count program, Dijkstra's shortest path algorithm, convex hull computation, and a graphics program. These examples demonstrate how easily algorithms can be translated into running programs using LEDA. The library is available for research and teaching purposes and can be used with any C++ compiler supporting templates. LEDA's efficiency is achieved through precompiled libraries, efficient implementations, and a novel item concept. Despite some performance trade-offs compared to hand-coded versions, LEDA offers significant convenience and generality. The library has been widely adopted in universities and research institutions, with applications in various fields such as code optimization, motion planning, and computational biology. The article concludes by discussing the scope and features of LEDA, emphasizing its comprehensive coverage of combinatorial and geometric computing. It also provides references for further reading and acknowledges the support from the German Ministry for Research and Technology and the ESPRIT Basic Research Actions Program.The article introduces LEDA, a comprehensive library for combinatorial and geometric computing, which aims to address the lack of a standard library in this area. Combinatorial and geometric computing, a core area of computer science, deals with data structures and algorithms for objects like graphs, sequences, points, lines, and convex hulls. The absence of a standardized library has hindered the impact of these areas on broader computer science applications. LEDA provides a wide range of data types and algorithms, including stacks, queues, lists, dictionaries, graphs, and geometric structures, along with precise specifications and efficient implementations. It supports parameterized data types and offers multiple implementations for many data structures, allowing users to choose the most suitable one. LEDA also includes a novel "item" concept to enhance efficiency in data structures. The article highlights four examples: a word count program, Dijkstra's shortest path algorithm, convex hull computation, and a graphics program. These examples demonstrate how easily algorithms can be translated into running programs using LEDA. The library is available for research and teaching purposes and can be used with any C++ compiler supporting templates. LEDA's efficiency is achieved through precompiled libraries, efficient implementations, and a novel item concept. Despite some performance trade-offs compared to hand-coded versions, LEDA offers significant convenience and generality. The library has been widely adopted in universities and research institutions, with applications in various fields such as code optimization, motion planning, and computational biology. The article concludes by discussing the scope and features of LEDA, emphasizing its comprehensive coverage of combinatorial and geometric computing. It also provides references for further reading and acknowledges the support from the German Ministry for Research and Technology and the ESPRIT Basic Research Actions Program.