There are more than 4.4 billion people in the Asia-Pacific region. In some areas, few people have mobile devices. In others, the market is so saturated with electronics that people deeply engage with their smartphones—more than consumers on any other continent, according to some estimates.

All of this helps explain why so many technology companies see the region as potentially lucrative. In one of the hotter areas of the technology industry, mobile communications applications, a wicked chat war is brewing. China’s WeChat, Japan’s Line, and Facebook’s WhatsApp (American in origin, but especially popular in Asia) are engaged in a fight for the hearts and mobile devices of billions of people.

“The chat apps are all competing with each other in a platform land grab across Asian markets,” says Shiv Putcha, an analyst for IDC based in Mumbai. “They have extended well beyond the original SMS replacement service to include entertainment, gaming, and now payments. In effect, they are fast becoming the mobile equivalents of the online ecosystems built by the likes of Google and Facebook.”

In preparation for the coming fight, the chat providers are building war chests and forging alliances to improve their chances of success. Tencent, the Chinese Internet giant, recently bought 15 percent of JD.com, the second largest e-commerce website in China, with the intention of adding a mobile payment function to its hugely popular WeChat platform. Tencent (which is Asia’s most valuable Internet company with a market capitalization that hovers around $159 billion) also plans to create an exclusive shopping channel for JD.com, thereby connecting WeChat’s 438 million young Chinese users to the e-commerce portal.

Japan’s Line Corporation is Tencent’s biggest Asian chat rival. The company has filed for an initial public offering on the Tokyo Stock Exchange and is expected to raise $9.8 billion. “Product innovation will be a strong differentiating factor at this level of chat app competition,” says Neha Dharia, an analyst at Ovum. “Line seems to have understood this change in the market and its I.P.O. move makes perfect sense.”

Meanwhile, consolidation is taking place in the market. Silicon Valley’s Facebook and Tokyo’s Rakuten have acquired WhatsApp and Viber, respectively, allowing the acquired companies to focus on developing new products and expanding their user base without having to worry about funds.

Viber, founded by four Israeli partners and acquired earlier this year for $900 million, is particularly interesting because it is considered to be a clone of Skype MSFT , the popular Microsoft-owned communications software. Some argue that Viber is better suited to the task than the real McCoy.

WhatsApp continues to enjoy massive global reach, but its future in Asia is unclear. Compared to rival applications, the service has limited functionality. Barring product improvements, its popularity could be dependent on its ability to leverage Facebook’s FB immense user base and integrate with its namesake network and messaging system—a possibility WhatsApp CEO Jan Koum dashed in February. “No plans for integration with Facebook whatsoever,” he said at an industry conference, suggesting a post-acquisition trajectory similar to that of Instagram.

“WhatsApp is for the global market but it’s weaker in Asia,” says Sandy Shen, an analyst for Gartner based in Shanghai. “WeChat is targeting the Chinese community worldwide, so it also has global presence. But its positioning is different.”

And still there are are others: South Korea’s Kakao and India’s Hike are also popular services but are not considered significant threats to WeChat and Line. “China is where the real battles will occur,” Putcha says. “Tencent is way ahead with WeChat and instant messaging service QQ. But Line is getting traction in Southeast Asia and India by offering free calls on top of all their other services.”

And that’s to say nothing of future competition. Alibaba, the world’s largest e-commerce company with annual sales exceeding those of Amazon and eBay combined, has started its own instant-messaging service called Laiwang. The company BABA is also developing mobile games, videos, and a mobile search service with the Beijing-based browser company UCWeb.

Why would Alibaba engage in such an effort? To counter Tencent’s partnership with its arch e-commerce rival JD.com, of course. (Tencent continues to stack its Internet platform with additional services. Most recently, it received permission from Chinese regulators to create a private bank.)

Which all goes to say that the battle over chat apps in Asia has only just begun.

Next, read:A risky bet on mobile e-commerce in Asia,” by Erik Heinrich.