Plot.ly is a complicated beast, it comprises of two technologies:
- A subscription-based in-browser interactive tool for building interactive visualisations
The plotly.js library is available to both R and Python programmers so that they may build interactive visualisations directly from those languages. In the R world, plotly is a first rate htmlwidget and works will in Shiny applications - read here for more details.
Free Accounts on Plot.ly
With a free account on plot.ly you can create an unlimited number of public visualisations, and can pull in data from up to 7 external data sources. All public visualisations may be easily "forked" by others and modified, however there is a complete audit trail of where the data initially came from - as shown in the diagram on this page.
The IDN recommends that small datasets can comfortably be uploaded directly to Plotly as you retain authorship via this audit trail, however there is not a canonical DOI for the data. You're therefore encouraged to use a free Plot.ly account for research outputs that do not require long-term availability or for developing teaching aids.