Hi,

Depends on what analysis you want to perform on it.

For GIS. mapping and modelling.. QGIS, online arc map are preferable. You can also use them for certain image analysis techniques.

For image processing techniques.. Matlab, grass GIS, ILWIS and many others are there

Hi,

I think that envi is a best software to analysis such data

Hi,

you can try use a SNAP software http://step.esa.int/main/

but useful of software will be depends on what analysis you want to execute.

I use GIS and envi both awesome

QGIS is open sources software you can dounload

If it is the freely available version you are searching for, I would suggest QGIS and IDRISI. I have worked mainly on classification using IDRISI and find it very efficient. However, ARCGIS, ERDAS, and ENVI are the most common softwares in GIS fraternity. As per my knowledge, all these provide support for IKONOS data.

Thank you all