How Europe's bold new rules for Big Tech could change the services you use

Apple users could soon install apps outside the App Store. WhatsApp users could message or video call friends using Telegram, and vice versa. And the search results users see on Google could change, with potentially major repercussions for smaller online businesses.

These are just some of the changes that could come about for consumers from new landmark legislation unveiled by European lawmakers last week that aims to bolster competition in online services. By imposing new regulations on technology platforms deemed to be dominant "gatekeepers," the Digital Markets Act (DMA) could result in sweeping changes to how EU citizens — and potentially consumers around the world — interact with major tech companies, including Amazon (AMZN), Apple (AAPL), Google (GOOGL GOOGLE) and Facebook parent company Meta (FB).

Regulators in several countries have proposed new rules to rein in Big Tech, but the EU proposal is among the most ambitious and may be the closest to becoming reality. According to Margrethe Vestager, executive vice president of the European Commission, the DMA could take effect as early as October, although it could be longer before consumers start to see changes as regulators determine which tech companies are covered by the law and the companies figure out how to implement the new rules.