Colossus vs Guzzle: What are the differences?

What is Colossus? I/O and Microservice library for Scala. Colossus is a lightweight framework for building high-performance applications in Scala that require non-blocking network I/O. In particular Colossus is focused on low-latency stateless microservices where often the service is little more than an abstraction over a database and/or cache. For this use case, Colossus aims to maximize performance while keeping the interface clean and concise.

What is Guzzle? PHP HTTP client that makes it easy to send HTTP requests and trivial to integrate with web services. Guzzle is a PHP HTTP client that makes it easy to send HTTP requests and trivial to integrate with web services.

Colossus and Guzzle can be categorized as "Microframeworks (Backend)" tools.

Some of the features offered by Colossus are:

• Clean Event-based Programming
• Seamless Integration with Akka
• Real-time Metrics

On the other hand, Guzzle provides the following key features:

• Manages things like persistent connections, represents query strings as collections, simplifies sending streaming POST requests with fields and files, and abstracts away the underlying HTTP transport layer.
• Can send both synchronous and asynchronous requests using the same interface without requiring a dependency on a specific event loop.
• Pluggable HTTP handlers allows Guzzle to integrate with any method you choose for sending HTTP requests over the wire (e.g., cURL, sockets, PHP’s stream wrapper, non-blocking event loops like React, etc.).

Colossus and Guzzle are both open source tools. It seems that Guzzle with 17.1K GitHub stars and 1.95K forks on GitHub has more adoption than Colossus with 1.14K GitHub stars and 100 GitHub forks.