There exist a vast number of extremely useful and versatile plugins for use with the Planets.nu website and game. Some are designed to work only with the original client, but most are designed for the new. None are actually hosted by Planets.nu, and every link to them is offsite.
Some of these plugins are known to conflict with others, and some aren't up-to-date at any given point in time. It is also possible that changes to the Client will cause an add-on to stop working, or will interfere with a plugin to such an extent that the Client will stop working. Some of the more useful plugins are in the process of being incorporated into the client software. Therefore, any specific information may be out-of-date at any point in time.
All information shown about a plugin is provided by the author, either directly, or from the on-line description of the plugin.
It should be remembered that no form of off-site content is either the property or responsibility of Planets.nu. Use at your own risk.
Late in 2018, Planets.nu released a new version of the Client. There are a few compatibility issues with plugins between the old Client and the new Client. Mcnimble has assembled a list of which plugins are conpatible on this offsite page.
This list shows the expected level of browser compatibility of plugins. Please note that just because a browser is shown as supporting plugins doesn't mean that every plugin will work properly under the browser. This is for informational purposes only, and is correct to the best of our knowledge. This information was extracted from Mcnimble's installation instructions.
If a browser isn't listed, it may, or may not, support plugins.
https://greasyfork.org/en/scripts/2618-planets-nu-improved-hover-text
Shows extra information when hovering over planets and ships. I especially like seeing the max population of a planet or what ship is being built at a base.
http://userscripts-mirror.org/scripts/show/130614
Ion storms throw your ships all over the place. But with this plugin, they'll still end up exactly where you want them.
http://userscripts-mirror.org/scripts/show/133919
Border agreements, hints about a homeworld location, planned routes ... How to track all this stuff? With Map Draw, you can just draw on the starmap.
https://greasyfork.org/en/scripts/6127-planets-nu-planetary-management-plugin
Tired of changing tax rates and building factories every turn? Tell this plugin about your planetary management strategy and it will take care of the turn-by-turn details.
https://greasyfork.org/en/scripts/2589-clan-display-and-temperature-addon-for-planets-nu-starmap
This plugin adds new functionality such as temperature, ownership, clans, closeness to completing a SB, and others to the map.
https://greasyfork.org/en/scripts/2596-planets-nu-fleet-ui
The fleet plugin adds a new pane to the ship map view that lets you control groups of ships - set group readiness, destination, speed, and see the fleets total cargo, minesweeping, minelaying, etc. If you have the ship list mod installed, the two actually work together letting you jump to the ship list display from a fleet view.
https://greasyfork.org/en/scripts/2591-color-coding-for-planets-nu
The Map Color plugin gives all objects for an enemy a fully customizable color - ships, minefields, planets, etc. It also lists ship names next to explosions on the map.
https://greasyfork.org/en/scripts/2592-planets-nu-improved-ship-list-view
The Ship List Plugin adds a number of functions which help analyze ship movements for potential mistakes, as well as letting you command fleets or individual ships based on location or destination - Friendly Code, ready status, and you can match another ships destination.
https://greasyfork.org/en/scripts/5994-planets-nu-enemy-ship-list-plugin
You've seen enemy ships, a few at a time, throughout the game. But how many Gorbies do they have? And where were they last seen? Enemy Ship List keeps this list for you automatically, but also allows you to make manual changes.
https://greasyfork.org/en/scripts/6442-planets-nu-idle-object-visualizer-plugin
The "ready checkbox" is a great timesaver for finding the ships that still need orders. But do you really want to cycle through your ships in random order? This plugin shows ready status from the starmap, so you can quickly cycle through ships in whatever order you wish.
https://chmeee.org/#planets.nu/RedrawAndFilter
So much information on the starmap, and each planet takes up how many pixels? This plugin keeps your starmap lean and mean, so you don't miss any details.
http://chmeee.org/project/planets.nu/wiki/ShowMessages
Shows ship explosions (and other message information) on the starmap for faster access.
http://chmeee.org/project/planets.nu/wiki/ShowNotes
Why write all those notes if you can't see them? This plugin lets you see all those notes directly from the starmap.
Also gives a summary of the ship types at each location.
https://greasyfork.org/en/scripts/5020-planets-nu-gravitonic-connections
Find hidden connections, in which a gravity well lets you travel more than 81 light-years in a turn. This plugin is similar to the connections you see by pressing Q, but adjusted based on the gravity wells.
The above list is only a sample of the many Planets.nu features that can be added or changed with plugins. For the most complete list of Planets.nu plugins known, please see http://www.planetsmagazine.com/gettoknowplanets/addons/available-mods-for-planets-nu/.
If you've never installed browser extensions before, check the "installation" section on this page: https://chmeee.org/#planets.nu