Feed readers are my learning project, I use it to learn new languages. I've built and rebuilt readers in vbscript, vb.net, c#, php and python. php and python have been the easiest since they have good parser libraries. Also I've used SQL Server, MySQL, SQLite and just JSON flat files. I think I've built something like 10 or so variations. In the last few I've expanded to not only pull from RSS and included Hacker News, Twitter and an enhanced pull for Reddit feeds. Though I'm not pulling Twitter currently because of some API changes that I've haven't bothered to spend time on.

Helpful hint if you need favicons for your reader you can use Google.

https://www.google.com/s2/favicons?domain=techmeme.com

The above is a load balancer for this url where the t1 subdomain may change to t[1-9] but this URL allows you to change the image size.

https://t1.gstatic.com/faviconV2?client=SOCIAL&type=FAVICON&...

I use it to grab and store sizes 16,32,48,64 of the icons with a monthly update ping.

My current iteration is built in python with a mysql backend. It's setup in a river of news style with an everything river and one for each feed and I generate topic bundles also. The feed engine is running every 15 minutes grabbing 40 feeds at a time but the static site generator is only running every 6 hours to keep me from spending all my time reading news. Since I pull in Reddit feeds I found that it's great for feed discovery.