Jul 20, 2023

Standalone JavaScript based from Mozilla 91-esr

Spidermonkey is the JavaScript interpreter from the Mozilla project.

Spidermonkey91 is a highly efficient and widely useful software port within the FreeBSD network, belonging to the ‘lang’ category. Known for its incredible stability and fast performance, it acts as a standalone JavaScript engine for embedding in applications. This article will delve into the practical usage of spidermonkey91, helping FreeBSD users understand its immense potential and efficiency.

Benefit and Pre-Requisites

Spidermonkey91 brings the power of JavaScript to a variety of other applications. It’s based on the same JavaScript engine which powers the Firefox web browser, enabling developers to embed JavaScript functionality in their apps. It gives them more flexibility and control over the specific functions of their software applications.

Before you begin using spidermonkey91, ensure that you are operating on the FreeBSD operating system, as this port is specific to it. Further, a fundamental knowledge of how ports work and how to utilize them is necessary. Although we won’t delve into port basics here, there’s a plethora of resources available, including FreeBSD’s own in-depth handbook [FreeBSD Handbook Ports]https//www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/ports.html.

Installing Spidermonkey91

Before moving on to the usage, let’s understand first how to install spidermonkey91. To install the port, simply run the following command

cd /usr/ports/lang/spidermonkey91/ && make install clean

To add the package instead, execute

pkg install lang/spidermonkey91

Once installed, you should be able to integrate JavaScript into your applications using this engine.

Using Spidermonkey91

Spidermonkey91 provides you with a -shell option that allows you to execute JavaScript code directly from your shell terminal. Type the following to open up the interpreter


This will open the shell interface where you can input JavaScript code directly. For instance,

js91 -e 'console.log"Hello, World!"'

The above command will print Hello, World! to standard output.

Moreover, you can use the shell to execute script files. If you have a JavaScript file, say test.js, you can execute it as follows

js91 test.js

Benefits of using Spidermonkey91

One of the significant advantages of using Spidermonkey91 as your primary JavaScript engine is its integration with the rest of the Mozilla platform. Scaling new heights of interoperability, if your software needs to interface with components like Gecko or Servo, Spidermonkey91 provides a seamless, convenient approach.

The Spidermonkey engine also features a wide range of tools and back-end services for your application. For instance, it supports ECMAScript 6th edition and some aspects of the 7th and 8th editions, giving you access to newer JavaScript features.

Spidermonkey91 also performs Just-In-Time JIT compilation of JavaScript code, which can greatly improve performance in many use-cases. This provides an additional edge for software applications demanding high performance.

Lastly, the Spidermonkey project is actively maintained and developed by Mozilla. This implies good support, frequent updates, and a roadmap that aligns with the broader web landscape. It provides a level of assurance to developers who choose to embed Spidermonkey in their applications.


In conclusion, Spidermonkey91 is a powerful and efficient piece of software. While the primary audience for Spidermonkey91 is developers creating applications, its utility filters down to the end-users who get to reap the benefits of highly optimized, feature-rich applications. Given the strong support and future-proof nature of the project, it’s a strong contender for anyone looking for a standalone JavaScript engine.

While using Spidermonkey91 for applications, it’s often necessary to validate their performance and security. For this, we recommend the use of FreeBSD ports like nmap for network exploration and security auditing. You can learn more about this tool from [our elaborative article here]https//freebsdsoftware.org/security/nmap.html.

By being open to new and powerful tools like Spidermonkey91, you can truly unlock the potential that FreeBSD has for software development.

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