Like the ModelBuilder of ArcGIS Desktop to run simultaneous geoprocessing tools, is there any model builder available in QGIS?
Sextante is a geoprocessing library that can be used from several GIS applications. I recommend you to use it from gvSIG as i think that it has the best integration. Sextante also allows (if you configure it properly) use algorithms from SAGA and GRASS.
Here you can see a video that shows how the modeler works.
Update: From March, qgis also has a Sextante plugin that works really well.
GRASS has a model builder that works pretty well (don't know how it compares to the Arc* one).
Victor Olaya, the developer of Sextante is currently working on Sextante for QGIS. It's work-in-progress and not yet ready for production use so use with care. You can watch a short demonstration of the Sextante model builder here: http://www.youtube.com/watch?v=LTUu-I2ouqU
Update Nov 2012: Sextante for QGIS is developing very well, as you can see eg. in this new case study: http://www.qgis.org/en/community/qgis-case-studies/pinhel-portugal.html
Update Jan 2016: Sextante is now a core plugin in QGIS recent versions, and it's called Processing. Check more information about in the QGIS Users Manual - QGIS processing framework. You can also get information about how to use the Graphical Modeler in here.
Now you can access a model builder in QGIS from the:
Processing menu -> Graphical modeler
I am glad to inform that we are currently working on SEXTANTE for QGIS. It should be ready soon, and it will include the modeler, which is what you are asking for.
Post is related to a rapidly changing event.
You may also consider some basic Python scripting to run multiple commands in series.
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