As the number of infections and deaths from the novel coronavirus rise drastically, governments, schools, and companies around the world are instituting more drastic measures to rein in the virus’s spread. The moves are causing companies to accelerate an already growing trend of working from home that companies had mentioned last month but that’s now playing out in their increased use of workplace software.

Quarantines, cancellations, and work-from-home policies have greatly driven up the demand for video and chat software that allows people to try and maintain some semblance of business as usual. In response, workplace software companies like Zoom, Microsoft, and Google have offered their software for free and have taken pains to make sure they can accommodate the growing demand from users.

Microsoft’s Teams saw a 500 percent increase in meetings, calls, and conference usage in China since the end of January, according to a spokesperson. Usage rose in the United States as well, at least among Microsoft employees, many of whom have been instructed to work from home. Last week, their chat volume on Microsoft Teams was up 50 percent, while video and audio meetings were up 37 percent compared with a week earlier.

Zoom wouldn’t comment specifically on growth in usership, but Zoom CFO Kelly Steckelberg told Yahoo Finance on Monday, “At the end of January if you took the run rate of our minutes usage at that point, we were on a run rate of a hundred billion annual meeting minutes and that is up pretty significantly since then.”

Slack wouldn’t comment on whether it’s seen increased usership or any issues with increased demand, citing a quiet period around its upcoming earnings.

Third-party data supports the reports of spikes in usage of these products. Productiv, a firm that helps companies track how their employees use software, saw Zoom usage increase more than 30 percent since the beginning of February for employers who put restrictions on travel (Zoom usage also increased for those who didn’t impose restrictions). Microsoft Teams usage among Productiv clients is up 20 percent in the first week of March compared to the first week of February.

While coronavirus has certainly caused demand for these apps to increase, it doesn’t hurt that Zoom, Microsoft, Google, and Slack are offering many of their products’ features for free. Zoom has lifted time limits on its video calls for the free versions in China, as well as for schools in Japan, Italy, and the US, by request.

“We really want to do what’s right, and the opportunity to get more people exposed to Zoom we think will reap benefits in the future,” Zoom’s Steckelberg told Yahoo.

Zoom stock is up more than 20 percent in the last month, a major outlier as the stock market as a whole is plummeting and fears of a recession are on the rise.

Microsoft is offering anyone its premium version of Teams for free for six months and has lifted existing user limits on its free version. The premium Teams product was already available for no extra cost to those who pay for the Office Suite, and Teams had already been free for many schools.

Similarly, Google announced last week that it would offer its enterprise videoconferencing features — for example, larger meetings of up to 250 people and the ability to record — for free to G Suite and G Suite for Education customers through July 1, 2020.

Slack has always had a free version. Lately, it has been trying to get the influx of new users up to speed quickly by offering free webinars with live Q&As, consultations by phone, and information on working-from-home best practices.

“Given that Microsoft and Google have both enabled free use of their premium conferencing and collaboration apps, Microsoft Teams and Google’s Hangouts Meet, these could be good tools for businesses that haven’t ordinarily paid for these services,” Lexi Sydow, senior market insights manager at App Annie, told Recode.

The growth in popularity of these apps is evident from download data. Zoom became the most downloaded business app in the US on iOS for the first time this week and it was the top business app in 11 other markets. (The No. 1 US business spot had previously been occupied by the job search site Indeed.) Teams rose to No. 4 in the App Store, while Hangouts Meet and Slack remained at 10th and 11th place, respectively. The situation was similar for the Google Play Store.

Meanwhile, in Italy, business apps like Google’s Hangouts Meet and Classroom were the most downloaded of any category of apps this week. Last week, App Annie noted that the country had seen a huge surge in downloads in business apps, with one week in February “marking the biggest week for Business app downloads in Italy ever.” The trend was similar in China, where business and education apps saw the biggest surge in downloads of an app category.

All this increased demand would be nothing if the software doesn’t work. Zoom, Teams, and Slack have said that they haven’t had any major issues and are continually preparing for increased demand. Downdetector has reported recent outages for Zoom, Teams, and Slack, but they were not severe enough to indicate that increased usage is causing work-from-home software to suffer.

“What we’re doing internally is really ensuring that we have capacity available to support all these free and of course our paid customers as well,” Steckelberg said. “Ensuring that our data centers have all the capacity that we need around the globe as well as that our customer success and support teams have the bandwidth to support all these needs.”

In a recent blog post, Microsoft detailed its efforts to keep Teams running smoothly for its increased number of users, including running “multiple instances of a service” in “geographically dispersed data centers.”

Slack also wrote in a blog post that its “highly distributed” architecture, redundancies, and frequent testing keep Slack up and running. Additionally, “The demands on our infrastructure do not change when employees shift away from working together in the same office; there is no difference in load on our systems whether people are connecting from their office, a cellular network, or their home.”

The coronavirus has pushed working from home from a growing trend to a central focus among those whose work is mediated by computers. Whether that lasts largely depends on the length and severity of the coronavirus outbreak — and whether the software that supports working from home stands up to its increased demands.

Clarification: This story has been updated to reflect that increased Teams usage in the US was among Microsoft employees and not the population at large. It’s also been updated to state that Google enterprise upgrades are only available to existing Google customers.