2017 announcement, the company stated that "we've been doing a bad job of keeping our open-source product repos up to date", partially because "open-source makes it hard for us to develop some features 'in the clear' ... without leaking our plans too far in advance", prompting the decision to archive its public GitHub repos. Hosting and servers , Reddit decommissioned its own servers and migrated to Amazon Web Services. Reddit uses PostgreSQL as its primary datastore. It uses RabbitMQ for offline processing, HAProxy for load balancing and memcached for caching. In early 2009, Reddit started using jQuery. Mobile apps In 2010, Reddit released its first mobile web interface for easier reading and navigating the website on touch screen devices. For several years, redditors relied on third-party apps to access Reddit on mobile devices. In October 2014, Reddit acquired one of them, Alien Blue, which became the official iOS Reddit app. Reddit removed Alien Blue and released its official application, Reddit: The Official App, on Google Play and the iOS App Store in April 2016. The company released an app for Reddit's question-and-answer Ask Me Anything subreddit in 2014. The app allowed users to see active Ask Me Anythings, receive notifications, ask questions and vote. Product and design changes The site has undergone several products and design changes since it originally launched in 2005. When it initially launched, there were no comments or subreddits. Comments were added in 2005 and interest-based groups (called 'subreddits') were introduced in 2008. Allowing users to create subreddits has led to much of the activity that redditors would recognize that helped define Reddit. These include subreddits "WTF", "funny", and "AskReddit". Reddit rolled out its multireddit feature, the site's biggest change to its front page in years, in 2013. With the multireddits, users see top stories from a collection of subreddits. In 2015, Reddit enabled embedding, so users could share Reddit content on other sites. In 2016, Reddit began hosting images using a new image uploading tool, a move that shifted away from the uploading service Imgur that had been the de facto service. Users still can upload images to Reddit using Imgur. Reddit's in-house video uploading service for desktop and mobile launched in 2017. Previously, users had to use third-party video uploading services, which Reddit acknowledged was time-consuming for users. Reddit released its "spoiler tags" feature in January 2017. The feature warns users of potential spoilers