What free programs should every GIS user have installed?
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- Google Earth, for viewing and creating KMZ/KML files
- Trimble Sketchup, for creating 3D models
- PointVue LE, Fusion/LDV, LAStools, for viewing LAS (LiDAR) files in 3D
- PyScripter, for Python scripting
- ArcGIS Diagrammer 10.0, for designing geodatabases and modifying schemas (ESRI XML workspace documents) (for 10.1 and for 10.2) (discontinued at 10.3)
- Visual Studio Express (C# or VB.NET), for .NET development
- SharpDevelop, alternative IDE to Visual Studio for .NET development -- also handy for converting between VB.NET and C#
- TortoiseSVN, TortoiseCVS, TortoiseGit, or TortoiseHg for version control on Windows
- Oracle SQL Developer, for poking around the back end of ArcSDE, running queries, etc.
- PrimoPDF, for printing/appending to PDFs
- LightShot, for quickly taking and uploading screenshots, or GreenShot which is similar but quite a bit more powerful/customizable (thanks @Mike Toews for mentioning it in one of the comments).
- VLC media player, for desktop video recording and video playback
- Open Broadcaster Software, for 2D and 3D video recording and screencasting (requires Windows Vista or newer)
- MSI Afterburner, for 3D video recording
- VirtualDub, for basic non-linear video editing
- XnView, GIMP, Paint.NET, and InkScape for various graphics tasks (each has their own strong suits)
- FileZilla, for FTP sites
- 7-Zip, for ZIP/RAR files
- UnxUtils - For a lightweight (native Win32) port of common GNU utilities like "tail" and "grep". Tail is great for displaying log files in realtime, while grep is a powerful (regular expressions-based) text search tool.
- Copy Path - A shell extension for Windows XP, Vista, 7, etc. that adds a "Copy Path" context menu item to files and folders in Windows Explorer. Makes short work of finding the full path (and also normalizes to UNC paths if it is on a mapped network drive). Great timesaver!
QGIS. Although I do most of my analysis using ESRI based tools, QGIS is extremely fast for quickly examining a shapefile, and zooming/panning/reading the attributes.
I don't mean this in a derogatory way, as QGIS is also a wonderful open-source desktop GIS; but for quick file opening/closing it's wonderful and the quickest I've found.
Fiddler is excellent.
Update
Suppose I'm looking at a Web App, like Esri's Redistricting Online ...
... and I become curious about the mapservices it uses. I can fire up Fiddler and see what Urls it is accessing.
I can right click and copy the url and paste into a web browser, since we're dealing with REST ...
http://redistricting.esri.com/arcgis/rest/services/Redistricting2010/Texas_2010/MapServer/1/query
I notice that as I add census blocks to a district, it simply does a query; it does not make a call to a geometryservice to union the blocks into a district as I would have expected. From this I can infer that Esri is holding back on us: somewhere in the client there must be code that unions geometries - but there is no such capability documented in the web SDK api.
Since there's no message on the root page of their redistricting mapservice saying I shouldn't use it, I guess I'm free to use it in my own app ... or at least until they implement the idea I've suggested.