Alltop and PopUrl are the most popular news aggregetores. Alltop was founded by Guy Kawasaki, Will Mayall and Will Mayall. You can use it to find about anything. For a example, if you want to know what happens in blogging world now you can select blogging topic of Alltop.
How do these sites work? They import the latest posts of popular websites and blogs. Then they categories those articles to their topics. After that, those articles are displayed in website under related topic.
OneNews WordPress Theme – Best Alltop/PopUrl Clone
OneNews WordPress Theme can be introduced as the best clone script for Alltop or PopUrl websites. It has two color themes. It is a mobile friendly theme and it comes with 4 custom widgets
WP RSS Aggregator
WP RSS Aggregator is also a WordPress plugin. It has a few premium add-on for more functionality.
Feed to Post : This plugin import all articles to blog posts only. After adding feed to post add-on you can import articles to custom posts.
Keyword Filtering: When you add a site, it syndicate all the posts of it. Using this add-on you can filter posts with keywords.
Excerpts & Thumbnails: You can display the excerpts and thumbnails also.
WP-Drudge is a WordPress theme. You can create a site like Alltop or PopUrl using this theme. You can buy this theme just 89$.
You can create a website like Alltop or PopUrl in just 5 minute.But you need to find good host to host this type of website. These sites use the lot of resources of server. So shared hosting is not good for creating a site like Alltop. You need to go for a VPS or dedicated server.