Hi, 

Cellprofiler, ImageJ, neuronstudio you can try

You can trace dendrits or axons with neuronstudio.

Also i've heard about imorph for 3D analyse

Good luck

Neuromantic http://www.reading.ac.uk/neuromantic/body_index.php

NeuTube http://www.neutracing.com/

these are very quick and easy to use. Neuromantic has a semi-automatic tracing mode and works on both old and new OS. NeTube requires a 64bit system and can trace dendritic processes much faster  (but you might have to correct eventual mistakes manually of course)

There is also an ImageJ plugin https://imagej.net/Simple_Neurite_Tracer

but is not as ready to use as these stand alone softwares.

I used Neurolucida neuron tracing Software (MBF Bioscience)