CheerpJ converts Java apps into JavaScript for the web

Convertation of applications and Java libraries  to web applications is no longer challenge. CheerpJ has managed to develop an unique technology
26 June 2017   1296

Java is a popular general-purpose programming language and computing platform

CheerpJ is the Java compiler for Web applications which serves to convert any Java application and library to a browser-based Web application effortlessly.

The CheerpJ Applet Viewer extension, created by Leaning Technologies and based on the CheerpJ technology, takes Java bytecode and turns it into JavaScript without needing the Java source or any plugin. Converted applications that can be deployed on a web server via both jar.js JavaScript and .jar files.


JavaScript is a lightweight interpreted or JIT-compiled programming language with first-class functions

Bidirectional liaison between Java and JavaScript is quite challenging for any JavaScript library and browser API from Java as well.

The most important features of Cheerp®J are following:

  • open-source compiler based on LLVM
  • native JavaScript memory model
  • clean access to HTML5 DOM
  • optimized performances and output size
  • JavaScript  interoperability

CheerpJ can generate Java archive (.jar) files as well as one single files including both reflection and dynamic classes.

The Applet Viewer extension compiles the Java applet on the fly, without relying on any remote server. The extension will be available on different popular browsers such as GWT(Google Web Toolkit) and Chrome that are running in a beta release now.

Compared with other technologies, Learning Technologies has no partial implementation of the Java runtime library, they rather convert than adapt to new applications. Technologies, which compile to JavaScript from other languages, include Scala.js, the Kotlin language, and Microsoft’s TypeScript.

Using The CheerpJ Applet Viewer requires no effort and installation of the extension proceeds just one click, creating the icon in the upper right corner of Chrome.
A restricted public release of CheerpJ is expected to be released in the upcoming July. As for a commercial version, it will roll out in the autumn.

Canonical to Represent Minimal Ubuntu

New version of Ubuntu is created for servers, isolated containers based on Docker and cloud systems
12 July 2018   106

Ubuntu team presented a simplified version of the base image - Minimal Ubuntu. It is designed for servers, isolated containers based on Docker and cloud systems. The release features high performance, minimal load time and automation of applications in the cloud.

The small footprint of Minimal Ubuntu, when deployed with fast VM provisioning from GCE, helps deliver drastically improved boot times, making them a great choice for developers looking to build their applications on Google Cloud Platform.

Paul Nash

Group Product Manager, Google Cloud

The authors of the project emphasize the size of the distribution kit, which "weighs" 157 MB, and also supports the main cloud systems like Amazon EC2, Google Compute Engine (GCE), LXD and KVM / OpenStack, each of which has its own optimized version of the package. In addition, the OS-based image for operating with containers based on the Docker platform, compatible with the Kubernetes.

Minimal Ubuntu is designed for automated execution, so it includes only a minimal set of tools. The distribution can be upgraded to a set of Ubuntu Server packages using the special utility "unminimize", which returns components that are convenient for interactive management.

According to Canonical representatives, the deletion of the manual control functions resulted in the acceleration of the load time by 40% and the reduction of the occupied disk space by 50%. At the same time, this release remained completely compatible with all the packages from standard Ubuntu repositories. Required packages can be installed using the standard package manager apt or using snapd, which are included in the distribution by default.

Two assemblies are available for download, based on Ubuntu 16.04 LTS and 18.04 LTS. You can download them on the official website.