I would like to transfer/convert my existing Gliffy diagrams to draw.io. Is this converting for free?
Yes, the transfer is free.
Additionally, there is also specific help by technical experts on https://support.draw.io/
Switch from Gliffy to draw.ioYou can gain more knowledge about why you should switch from Gliffy to draw.io. You can read your way through the advantages regarding usability and economic benefits for the license.
Comparing draw.io, Gliffy and LucidchartAn additional comparison of the three popular diagram tools draw.io, Gliffy and Lucidchart can be also helpful.
Weblog and general information about draw.io for ConfluenceThere is also a weblog under https://drawio.seibert-media.com/. We can also give you some general information and detailed documentation for draw.io for Confluence.