Top ten cool things about Manifold:

1. Vast content. Everything you could ever want in a GIS, expertly implemented with lavish attention to details. Endless projections, import/export formats, capabilities. The sheer completeness and breadth and depth of the package is breath-taking.

2. All the right layers. Works with vector drawings, raster images, surfaces and 3D terrains in one seamless, standard Windows GUI. Combines in a GIS many capabilities usually found only in CAD, image processing tools or graphics arts editors, such as powerful vector editing or image editing.

3. Fun for one or many. Work as an individual, in a workgroup or combine with thousands of others in an enterprise. Simultaneous multiuser editing of drawings with conflict resolution. Shared components. Share data with other people, easily. Huge scalability for enterprises while being easy to use in small firms.

4. Killer DBMS. By far the best built-in DBMS capabilities of any GIS plus super-tight integration with database systems, with read/write/edit storage of drawings and images either locally or in external DBMS servers. Direct connections to Oracle without need of middleware, and fast and easy "spatial" use of popular DBMS packages like SQL Server, MySQL, DB2 and many others. Oracle, SQL Server and IBM DB2 provided at no additional charge.

5. Spatial SQL. Not just SELECTs, but INSERTs, UPDATEs, PIVOTs and lots of other things too. Works seamlessly with data stored externally in a DBMS server or locally within Manifold with no external DBMS required. Simultaneously combine vector, raster image, surface analytic and geocoding extensions in the same spatial query. Select all pixels in a satellite image that have a given slope in the underlying DEM and also lie within a 200m buffer zone of 123 Main Street but are more than 50 feet away from a stream or a road. Cool stuff like that.

6. Built-in Integrated Internet Map Server (IMS). Create your map and publish it on the web using the same tool. Completely customizable. Includes OGC standards like WMS and WFS-T. Host your own rocket-fast, 64-bit IMS server with unlimited web sites and hits.

7. Live image servers. Stream live imagery that's automatically tiled and mosaicked together from Microsoft Virtual Earth, Yahoo, NASA World Wind, TerraServer, Google and other online mapping sites. This part is particularly jaw-dropping cool. Vital for parts of the world where GIS data and satellite imagery is hard to obtain.

8. Killer analytics for vector objects, images and surfaces. Simple things you can call by pressing a toolbar button as well as a sophisticated formula language. Intense topology and spatial overlays that can simultaneously deal with points, lines and areas with arbitrarily complex topologies or pathological geometries even when different projections are being used.

9. Outstanding programmability. Rich and extensive object model using your choice of standard Microsoft languages like .NET languages or ActiveX scripting languages. Create your own applications based on Manifold. Built-in development environment and debugger. Automatic syntax coloring for scripts and queries.

10. Rock solid, fast and affordable in both 32-bit and 64-bit Windows versions (running 64-bits native, not as a 32-bit emulation) with transparent support for multicore processors. Does more and costs far less than any other full-power GIS.

A bonus item: Great community.