Here I am sharing the tools I have used for causal loop diagramming:-

Paper and pen or pencil and eraser

Whiteboard or Blackboard

Miro or Jamboard: [https://miro.com/ Miro site] [https://jamboard.google.com/ Google Jamboard]

Plectica: [https://beta.plectica.com/ Access site]

Kumu:[https://kumu.io/ Access site]

Insightmaker:[https://insightmaker.com/ Access site]

Loopy: [https://ncase.me/loopy/ Access site] Online, Colourful, Brings CLDs to life, Engaging for kids

Cauzality: [https://cauzality.com/ Access site] Online, Collaborative, Directive, Loop and polarity identification

Vensim PLE: [https://vensim.com/free-download/#ple Access site] Free, Powerful, Loop identification, Driver trees, Stock flow diagrams, Full simulation capability

Vensim Pro:[https://vensim.com/vensim-software/ Access site] Full depth driver trees

STELLA, iThink: [https://iseesystems.com/store/products/stella-online.aspx Access site] Supports stock flow diagrams and simulation

Powersim: [https://www.powersim.com/main/download-support/technical_resources/free-downloads/ Access free tools]