MapCollaborator is a highly customizable map wiki developed by GreenInfo Network that allows organizations to collect a wide range of geographic data and related information from any interested user. Using an intuitive interface with simple, guided steps, invited users or the general public can review data, post notes, draw new features, edit over current features, or upload GIS files for immediate display. The MapCollaborator platform utilizes a variety of open source geospatial tools. The application’s foundation is constructed using a PostGIS database, MapServer WMS/WFS layers and GeoJSON for dynamic data, TileCache layers for static data, OpenLayers for map display and feature editing, and the OGR Python API for file handling. These components are wrapped in a CodeIgniter MVC web framework to create an extensible, repeatable deployment that adapts to specific project needs. This presentation proposes to explain and discuss the open source infrastructure supporting MapCollaborator and demonstrate examples of its use. Each instance of MapCollaborator is its own Edition, tailored to the complexity of the data and customized to meet the requirements of its particular project. An example implementation of the platform is the Anza Trail Edition (http://www.mapsportal.org/mapcollab_anza/), which facilitates Trail Partners such as agencies, non-profits, and volunteers to assist the National Park Service in documenting recreational trails and resources along the Anza National Historic Trail in Arizona and California. Database edits and additions collected through MapCollaborator are reviewed by project managers via a robust custom administrative interface that allows reviewers to approve, archive, or delete edits as well as download data summaries, track application activity, and generate emails to participants. By melding the best of open source GIS and web development tools, GreenInfo has created a versatile and intuitive application framework that can support the collaborative development and review of almost any kind of spatial dataset.