How to download and setup io
Open terminal and run command
                                            git clone https://github.com/io-gui/io.git
                                        
                                        git clone is used to create a copy or clone of io repositories.
                                        You pass git clone a repository URL. it supports a few different network protocols and corresponding URL formats.
Also you may download zip file with io https://github.com/io-gui/io/archive/master.zip
Or simply clone io with SSH
                                            [email protected]:io-gui/io.git                                    
                                    If you have some problems with io
You may open issue on io support forum (system) here: https://github.com/io-gui/io/issuesSimilar to io repositories
Here you may see io alternatives and analogs
three.js aframe plotly.js plotly.py spritejs gpu.js tfjs tfjs-core xterm.js plotly.R Babylon.js lume tangram terriajs pixijs bgfx webglstudio.js herebedragons phenomenon G2 VivaGraphJS vizceral HTML-GL Blotter gl-react glslViewer Wagner THREE.MeshLine fieldplay polygon-shredder