3Scale is described as '3scale provides an out of the box cloud API management platform and infrastructure for developers, and companies to securely open, control, manage, operate and monetize their API to third parties (e.g. developers, business partners, etc.)' and is an website in the Development category. There are more than 10 alternatives to 3Scale, not only websites but also apps for a variety of platforms, including Linux, Windows, Mac and Self-Hosted solutions. The best alternative is Kong, which is both free and Open Source. Other great sites and apps similar to 3Scale are Tyk (Free, Open Source), VMware AirWatch (Paid), WSO2 API Manager (Free, Open Source) and apiman (Free, Open Source).
Kong is a scalable, open source API layer (also known as a API gateway, or API middleware). Kong runs in front of any RESTful API and is extended through plugins, which provide extra functionalities and services beyond the core platform.
AirWatch by VMware is the leader in enterprise mobility management (EMM). With industry-leading identity, productivity and collaboration solutions, we enable end users with a seamless digital workspace.
Fusio is an open source API management platform which helps to build and manage REST APIs. Fusio provides all tools to quickly build an API from different data sources yet it is possible to create complete customized responses.
APIBond is a service that acts as a proxy where you can configure an existing API. One problem with the existing APIs in the market is the lack of customization. Eg. Twitter API calls returns the same response to everyone.