How to download and setup github
Open terminal and run command
                                            git clone https://github.com/atom/github.git
                                        
                                        git clone is used to create a copy or clone of github 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 github https://github.com/atom/github/archive/master.zip
Or simply clone github with SSH
                                            [email protected]:atom/github.git                                    
                                    If you have some problems with github
You may open issue on github support forum (system) here: https://github.com/atom/github/issuesSimilar to github repositories
Here you may see github alternatives and analogs
atom 30-seconds-of-code classroom gogs harness hub phabricator gitsome viz github-cheat-sheet android-dev-sources curriculum gitignore tips git-extras diff-so-fancy gitea husky ungit git-recipes gitbucket libgit2 tig git-lfs decap-cms desktop pure git-standup githug legit