I was looking for the same thing and found ImageJ/Fiji being the only totally free deconvolution option. There are many plugins to choose from. The bottleneck in my experience is that you have to create the correct PSF for your stacks. Everything afterwards is rather simple as long as your computer has enough working memory.
Hi Robert and sorry for delayed response. I normally use Richardson-Lucy with TV regularization which is included in DeconvolutionLab. I also use another plugin for Fiji called Iterative Deconvolve 3D. However as Tim pointed out PSF generation is very critical to achieve good results. For this I use PSF Generator plugin.