libev VS Boost.Asio

Compare libev vs Boost.Asio and see what are their differences.


Full-featured high-performance event loop loosely modelled after libevent (by enki)


Asio C++ Library (by chriskohlhoff)
Our great sponsors
  • SonarLint - Deliver Cleaner and Safer Code - Right in Your IDE of Choice!
  • Scout APM - Less time debugging, more time building
  • SaaSHub - Software Alternatives and Reviews
libev Boost.Asio
3 11
1,267 3,385
- -
0.0 9.3
over 1 year ago 12 days ago
Shell C++
GNU General Public License v3.0 or later -
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.


Posts with mentions or reviews of libev. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2022-03-24.


Posts with mentions or reviews of Boost.Asio. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2022-05-02.
  • Ask HN: What are some examples of elegant software?
    22 projects | | 2 May 2022
  • The Lisp Curse
    11 projects | | 25 Mar 2022
    I like working in C++, after a decade of working in Java, Python, Javascript and Clojure, I find working in C++ (which I learned before these other languages) to be quite fun and pleasant, at least with relatively modern C++.

    I've been, on and off, working on a little toy game engine, for a few years. Its a mix of keeping up with C++ advancements, learning various concepts like physically based rendering, and just the fun of crafting a big project, with no constraints other than my time and ability, no deadlines, no expectation of releasing anything. Its cathartic and enjoyable. I really do enjoy it.

    Last September, I got frustrated with something I was working on in a more serious capacity. It was some server software, it responded to HTTP requests, it accessed third party services over HTTP and Websockets, it talked to a Postgres database. Overall it was an event driven system that transformed data and generated actions that would be applied by talking to third party services. The "real" version was written in Clojure and it worked pretty well. I really like Clojure, so all good.

    But because I was frustrated with some things about how it ran and the resources it took up, I wondered what it would be like if I developed a little lean-and-mean version in C++. So I gave it a try as a side project for a few weeks. I used doctest[1] for testing, immer[2] for Clojure-like immutable data structures, [3] lager for Elm-like application state and logic management, Crow[4] for my HTTP server, ASIO[5] and websocketpp[6] for Websockets, cpp-httplib[7] as a HTTP client and PGFE[8] for Postgres, amongst some other little utility libraries. I also wrote it in a Literate Programming style using Entangled[9], which helped me keep everything well documented and explained.

    For the most part, it worked pretty well. Using immer and lager helped keep the logic safe and to the point. The application started and ran very quickly and used very little cpu or memory. However, as the complexity grew, especially when using template heavy libraries like lager, or dealing with complex things like ASIO, it became very frustrating to deal with errors. Template errors even on clang became incomprehensible and segmentation faults when something wasn't quite right became pretty hard to diagnose. I had neither of these problems working on my game engine, but both became issues on this experiment. After a few weeks, I gave up on it. I do think I could have made it work and definitely could go back and simplify some of the decisions I made to make it more manageable, but ultimately, it was more work than I had free time to dedicate to it.

    So my experience was that, yes, you can write high level application logic for HTTP web backends in C++. You can even use tools like immer or lager to make it feel very functional-programming in style and make the application logic really clean. Its not hard to make it run efficiently both in terms of running time and memory usage, certainly when comparing to Clojure or Python. However, I found that over all, it just wasn't as easy or productive as either of those languages and I spent more time fighting the language deficiencies, even with modern C++, than I do when using Clojure or Python.

    I think I would think very long and hard before seriously considering writing a web backend in C++. If I had the time, I'd love to retry the experiment but using Rust, to see how it compares.










  • Learning Standard C++ as the New Language
    1 project | | 11 Mar 2022
    > the lack of good c++ libraries for common tasks in systems programming (like Sockets, or networking - still experimental after 40+ years!!)

    I don't think it's that shocking, is it? In most languages the networking support is basically just the C socket API exposed as well. A good API is a good API, it shouldn't really matter how it's implemented.

    Also seems like a massively unfounded leap to go from "the standard library doesn't have it" to "complete lack of good C++ libraries for common tasks". C++ has never been a "batteries included" language. That doesn't mean good libraries don't exist for it. Boost is very common in the C++ world, for example. And that "experimental" networking library is basically just asio but adopted by the standard library, and asio is not experimental or unstable:

    > Python for ex. might have C code behind the scenes, however you will interact with the C library in a pythonic way

    Kinda odd to use Python as an example when it just exposes C sockets pretty much directly and entirely non-pythonicly

    > In contrast, with C++ your program has Hodge podge of high-level constructs like std::vector, string, RAII etc.. and suddenly you are in the void, malloc, free land with your C code. The mental model of lifetime/memory of objects in your program is inconsistent and burdensome. People would rather program everything in C, at least it will be consistent albeit very low level.

    Eh? No, people would just make a tiny wrapper around the C APIs and call it a day. It's a pretty odd stance to take to say that to avoid writing ~100 lines of C-style C++, you should instead write 10k lines of C?

    Also other than void (which is in C++, too), you shouldn't be encountering malloc or free when calling C functions. That's not how any good C API works, and it's certainly not how the continuously mentioned socket APIs work.

  • P2300 (Sender/Receiver) is DEAD in the water for C++23 !!!
    5 projects | | 15 Feb 2022
    When was it? Executors (or proto executors if you want) were a thing in ASIO at least since early 00s -
  • Can you guys recommend a multiplatform alternative to POSIX sockets?
    3 projects | | 5 Jan 2022
    Take a look at asio (
  • Boost v1.78.0
    7 projects | | 7 Dec 2021
    As the commit ( explains, you can have io_uring to support the new I/O objects (i.e. files), but still using the epoll reactor for the other I/O objects. And that seem to be the only reason why the eventfd is there: you are still using epoll, but with io_uring through the eventfd to support things epoll doesn't support.
  • Retiring boost from my codebase
    11 projects | | 29 Jul 2021
    Standalone asio is the same library as boost::asio. It is the same developer that just makes a boost and non-boost version. The docs are at
    11 projects | | 29 Jul 2021
    That's not even considering transitive dependencies. For instance, asio is at module level 17, so it's not even worth listing its dependencies, while asio has a perfectly fine standalone version at "level 0" completely compatible with the STL. So if you need some basic utility like base64 encoding, you are probably bringing almost all 164 boost libraries into your project.
    11 projects | | 29 Jul 2021
  • What to do after intermediate c++ ? [ PLEASE GIVE ME IDEA ME BUILDING APPLICATION]
    3 projects | | 4 Apr 2021
    Asio is also available as a stand-alone library.

What are some alternatives?

When comparing libev and Boost.Asio you can also consider the following projects:

libuv - Cross-platform asynchronous I/O

libevent - Event notification library

C++ Actor Framework - An Open Source Implementation of the Actor Model in C++

Oat++ - 🌱Light and powerful C++ web framework for highly scalable and resource-efficient web application. It's zero-dependency and easy-portable.

C++ REST SDK - The C++ REST SDK is a Microsoft project for cloud-based client-server communication in native code using a modern asynchronous C++ API design. This project aims to help C++ developers connect to and interact with services.

POCO - The POCO C++ Libraries are powerful cross-platform C++ libraries for building network- and internet-based applications that run on desktop, server, mobile, IoT, and embedded systems.

uvw - Header-only, event based, tiny and easy to use libuv wrapper in modern C++ - now available as also shared/static library!

asyncio - asyncio is a c++20 library to write concurrent code using the async/await syntax.

rotor - Event loop friendly C++ actor micro-framework, supervisable