Developing a web mapping application? Why to reinvent the wheel while there is a framework that offers all the web mapping functionalities adaptable for your needs! Oskari is a modular map application framework for easily building varied web mapping applications. Applications can be composed by selecting functionalities from existing components, and custom extensions can be created and attached to applications easily. The existing components range from basics like layer selection and location search to more advanced functionalities like thematic maps and analysis. This presentation enables you to package your code to be part of Oskari, speed up your development by using ready-made tools and easily add server-side functionality to the existing implementation. Techstack includes Javascript, OpenLayers 2/3, Java, Geotools, Geoserver, PostgreSQL with PostGIS. Oskari is used in a wide range of different national and international web mapping services and it is continuously developed to better serve the changing requirements both by adding functionalities and perfecting the existing ones. Come and join the fast-growing group of Oskari Developers!