Here you can find the Sterne plugin for download. It runs on the (as of date) current WordPress Version 6.0.2.
It allows you to add "rating" stars to your headlines and posts. The plugin works by replacing predefined text by little star images, see below on how to achieve that. It is free to use and modify.
Please install the plugin by uploading it to your wordpress installation and extracting the ZIP file in the "plugins" folder. It is usually found in the folder "wp-content". The installation contains a sub-folder "img" which contains the actual rating star images. If you want to create your own rating system (see below) this folder must be writable by the wordpress installation.
Example: Stern(4,g) within the text of your post will give you two filled gold stars and three empty stars: . Points are from 0-10. 0 = 5 empty stars, 10 = 5 filled stars. Predefined colors available are: s = silver/grey, r = red, g = gold, b = blue.
Stern(points,totalpoints,red,green,blue). points can be an arbitrary number, but must be less than totalpoints, which should be an even number. red, green and blue denotes the color which is used to 'tint' an grey source picture. For simplicity I use full color saturation so you might need to experiment a little.
Stern(5,8,50,250,250) will look like this: (5 out of 8)
Stern(13,20,250,250,50) will look like this: (13 out of 20)
The colors red, green and blue must be values from 0 to 255.
Note: the source images can be exchanged! So if you're not satisfied with the stars, e.g. you want to make them bigger feel free and replace those files. Source images must be transparent, indexed gifs. Colorless is preferable (but not required) to get consistent results. Color change does not work with grey colors.