Force.com IDE Is Being Retired in October 2019
Where: This change applies to Lightning Experience, Salesforce Classic, and all versions of the Salesforce app in Enterprise, Performance, Unlimited, and Developer editions.
When: On October 12, 2019, we will no longer provide support or updates of any kind for Force.com IDE. We will also begin archiving documentation and removing download links for the product on that date.
How: We recommend that you start migrating to Salesforce Extensions for Visual Studio Code or one of the great tools made by our partners. For more information, see The Future of Salesforce IDEs on the Salesforce Developers Blog.
The https://github.com/forcedotcom/idecore repository will be archived on October 12, 2019. The source code will remain available in the repository, but the repository will no longer accept pull requests. To contribute to Force.com IDE after the repository is archived, create a fork. For details about archived repositories, see About archiving repositories in GitHub Help.