In the world there are different projects making software, some off these software is free to use.This site will only link to sites which provide free software. 

From the EfficienSea Project [1]:

• DaMSA AisLib - Java library for handling AIS messages:  https://github.com/dma-ais/AisLib
• EfficienSea AIS VHF Datalink Manager: https://github.com/DaMSA/EAVDAM [2]
• Extended INS https://github.com/DaMSA/ee-INS [3]

From Arundale [4]:

• A free AIS Decoder and NMEA router: http://nmearouter.com/docs/ais/ais_decoder_v3_downloads.html

From OpenCPN [5]:

• A free multi platform Chartplotter and GPS Navigation software: https://opencpn.org/OpenCPN/info/downloads.html [6]

From sourceforge:

• A free mindmap program: http://freemind.sourceforge.net/wiki/index.php/Main_Page [7]
• A free UML program: http://alexdp.free.fr/violetumleditor/page.php [8]