Floe

If you're among the more nostalgic ones, you probably remember when chatting to others via IRC was pretty popular and might want to try doing it again from time to time.
Luckily for you, there are several software solutions that can help you relive that part of your past by providing you with all the necessary means. One of them is Floe.

Connect to the IRC network

If you are an amateur of chatting to other IRC users, you can turn to this application, since it lets you do this quickly and without efforts. However, understanding and operating its controls with minimum difficulty requires that you have medium PC skills or at least some experience with similar software.
Unlike other similar apps, Floe doesn't pack a set of pre-configured servers. Therefore, you will have to insert the desired servers into the application manually.

Simple interface

This application comes with a simplistic, transparent interface that enables you to set the opacity of the background and overall window alike. It is possible to customize the minimum tab width, set the tab strip position, minimize the app to the system tray, detach incoming queries and adjust the color schemes according to your preferences.
The text formatting can also be modified by changing the font family and text size, enable timestamps, toggle tabular view and auto size columns.

Adjust download-related settings

You can choose a range of ports that allow downloading contents from this app, set a default download folder on your computer and manage a list of potentially dangerous extensions by simply typing them in the dedicated field.
The application provides you with support for proxy, in case you want to anonymize your connection and also lets you set custom sounds for various events.

Lightweight IRC client with transparent window

All things considered, Floe is a simple app that provides you with all the basic capabilities of a standard IRC client, a simple interface with adjustable opacity and proxy support. However, note that no servers are preloaded into the application and you need to import them manually.