Xuv package for Imaris (http://www.xuvtools.org/)
Xuv tools is a free, open source and fully automated 3D stitching software for confocal microscopy images.
The goal of XuvTools is to provide tools, that combine multiple microscopic recordings to obtain a larger field of view (“stitching”) and a higher dynamic range (“HDR” recombination), or better resolution (multi view reconstruction) when working with multiple 3D confocal image stacks. XuvTools runs on Windows Linux and Mac computers and supports 32 and 64 bit operating systems (64 bit preferred).
You can find our paper on stitching here:
PDF on Publisher site (free access)
Abstract of the paper
We also presented stitching with XuvTools with the following posters:
XuvTools Cheatsheet - Highly Recommended
A very condensed collection of XuvTools specifics and operation on one page. Includes some notes on microscope setup, and some general facts.
Worm5 / C.elegans
C.elegans worm from publicly available testdata (by Peter Meister, FMI Basel)
worm5 stitched:

sxn3_w1RGB-488nm, sxn3_w2RGB-561nm / Mouse brain
Mouse brain (by Dominique Spirig, FMI Basel)
sxn3_w1RGB-488nm, sxn3_w2RGB-561nm stitched:

To15100740xm / Neuron filaments
Neuron filaments from publicly available testdata (by Ivan Galimberti, FMI Basel)
To15100740xm stitched:
Video Tutorials - Highly Recommended