The term Progressive Web App (PWA) was coined in 2015. Since 2018 PWAs can be installed on all relevant operating systems and can also be executed offline. However, there is still a certain difference in functionality between PWAs and their native counterparts. With Project Fugu, the gap should continue to shrink.

When Steve Jobs introduced the iPhone in 2007, there was no mention of apps or the App Store. Instead, developers were asked to write web applications based on HTML to bring third-party applications to the new smartphone. The advantages are obvious: Web applications are cross-platform executable, run in a sandbox and do not have random access to native interfaces. Probably not least because of the last two points, Jobs was flirting with the web as an application platform. But the low performance due to the initially weak hardware and the not very distinguished capabilities of the web ultimately led to a change of mind at Apple, so they offered a Software Development Kit (SDK) for native development later.

However, a lot has happened on the web since then: Modern JavaScript and WebAssembly engines achieve almost native performance and CSS3 animations run very smoothly. HTML5 brought a lot of interfaces to the web, including local storage technologies and access to the user’s location. WebGL brought hardware-accelerated 3D visualizations and WebRTC brought peer-to-peer based real-time communication. Then along came Progressive Web Apps, which can be run offline with the help of Service Workers and, thanks to the Web App Manifest, also be present on the home screen or in the program list of the respective operating system. From there, the PWA can hardly be distinguished from native applications. Figure 1 shows Spotify’s Progressive Web App, which is very similar to its native counterpart. Only a few years ago, we would not have expected all these functions from the web. But despite all efforts, a certain gap between web applications and native apps is still visible today.

Fig. 1: Spotify as a Progressive Web App: Hardly any different from the native version.

Mission: A more powerful web

The three Chromium contributors – Google, Microsoft and Intel – now want to change this and have joined forces to create the Web Capabilities Project, better known by the code name Project Fugu. The aim of the project is to make missing features, that might still prevent developers from implementing their application as a web solution today, available on the web. Project Fugu APIs should be suitable for cross-platform use, where appropriate. In particular, no distinction between platforms should be required, opposed to how it currently is used with other cross-platform approaches. Instead, the web browser is in charge of calling the correct native interface. All three companies have an interest in powerful web applications: Google’s own web browser, Chrome, and the operating system, Chrome OS, for which Progressive Web Apps are, of course, ideally suited, are based on the open source browser Chromium. Microsoft recently gave up implementing its own browser engine, and the new version of Microsoft Edge is also based on Chromium. Since the Microsoft Store application marketplace has never really taken off, the company is pleased about the additional range of applications that Progressive Web Apps bring. Intel, on the other hand, sells hardware, and the demand from a stronger web would increase on two sides at once—for clients and servers.

Today, developers are often forced to develop applications natively or use wrapper approaches like Apache Cordova or GitHub’s Electron. These projects package a web application in a native application framework for mobile devices (Cordova) or desktop systems (Electron). The web application can then use this native application framework to access all interfaces...