Welcome to the website for IFL 2013, the 25th Symposium on Implementation and Application of Functional Languages. IFL 2013 is organized in cooperation with ACM/SIGPLAN. The goal of the IFL symposia is to bring together researchers actively engaged in the implementation and application of functional and function-based programming languages. IFL 2013 will be a venue for researchers to present and discuss new ideas and concepts, work in progress, and publication-ripe results related to the implementation and application of functional languages and function-based programming.