Top 20 NuGet log4net Packages

A modern high performance cross platform wrapper around Log4Net.
Adds detailed tracing to any method without modifying your source code. Several backends are available as separate NuGet packages. An official PostSharp pattern library.
Contains a set of interfaces to be implemented by any logger.
Official log4net integration for Sentry - Open-source error tracking that helps developers monitor and fix crashes in real time.
Castle Windsor logging facility lets you easily inject loggers into your components. It offers integration with most popular 3rd party logging frameworks like log4net, NLog and Serilog (see Castle Core docs).
JavaScript logging package that lets you log exceptions, AJAX timeouts and other client side events in your server side log. Supports .Net Core 2.0+ only. For ASP.NET 4.x (.Net 4.5.2+), install version 2.30.0 of this package.
Log4Net appender which sends logs to the Sumo Logic machine data analytics platform.
NLog appender which sends logs to the Sumo Logic machine data platform.
An AWS Log4net appender that records logging messages to Amazon CloudWatch Logs.
Unity adapter for log4net
log4stash is a log4net appender for easy logging of exceptions and messages to Elasticsearch indices. You can configure few filters to analyze log events before they got sended to Elasticsearch similar to the filters on logstash.
Shared library used by .NET log appenders uploading to Sumo Logic.
Rollbar collects errors that happen in your application, notifies you, and analyzes them so you can debug and fix them.
log4net logging provider for WeihanLi.Common.Logging, and log4net extensions, see details
Rapid7 Insight logging support log4net library
Log Audit.NET Audit Trail using Apache log4net™
PostSharp.Patterns.Diagnostics: support for Log4Net.
Redistributable components for package 'PostSharp.Patterns.Diagnostics'. This package should only be installed as a dependency. (This is not the package you are looking for).
Allows to configure Log4net as Microsoft Extensions Logging handler on any ASP.NET Core application. Original code proposal by @anuraj -->
Log4Net client library for the Google Cloud Logging API.