With a dual 'open'-strategy the department of geoinformation at the canton of Zurich/Switzerland opts for a strategic orientation towards open source and open data: Open in the sense of an open web-mapping- infrastructure based on open source components: Mapfish Appserver was developed as a framework for building web map applications using OGC standards and the Mapfish REST protocol. It is freely available under the new BSD-license (http://mapfish-appserver.github.io/). The Ruby on Rails gem comes with the following out-of-the box features: - Organize maps by topics, categories, organisational units, keywords and more - Combine maps with background and overlay topics with adjustable opacity - Import UMN Mapserver mapfiles to publish new topics within seconds - Fully customizable legends and feature infos - Creation of complex custom searches - Rich digitizing and editing functionality - Role-based access control on topic, layer and attribute level - Access control for WMS and WFS - Rich library of ExtJS 4 based map components - Multiple customizable viewers from minimal mobile viewer to full featured portal - Multi-site support - Built-in administration backend - Self-organized user groups maps.zh.ch, the official geodata-viewer of the canton of Zurich, was developed using Mapfish Appserver. It contains more than 100 thematic maps and is considered an indispensable working tool for everyone working with spatial data in the canton of Z?rich/Switzerland. 'Open' in the sense of Open Government Data: Zurich is the first canton participating in the national open data portal opendata.admin.ch. The portal has the function of a central, national directory of open data from different backgrounds and themes. This makes it easier to find and use appropriate data for further projects. The department of geoinformatics aims to open as many geo-datasets as possible for the public by publishing them on the national OGD-portal. The open geodata is issued in form of web services ? Web Map Services (WMS), WebFeature Services (WFS) and Web Coverage Services (WCS) - and contains a wide range of geodata from the fields of nature conservation, forestry, engineering, infrastructure planning, statistics to high resolution LIDAR-data.