Since the first CRAN release of future in June 2015, its uptake among end-users and package developers have grown steadily. During October 2023, future was among the top-0.8% most downloaded package on CRAN (Figure 1) and there are 319 packages on CRAN that directly depend on it (Figure 2). For map-reduce parallelization packages future.apply (top-0.9% most downloaded) and and furrr (top 1.3%), the corresponding number of packages are 135 and 111, respectively. If we consider recursive dependencies too, that is, packages that use the future package either directly or indirectly via another package, then 85% of all ~20,000 CRAN packages may rely on the future framework for their processing.
Figure 1: The download percentile ranks for future, future.apply, furrr, and foreach averaged every four weeks. future is among the top-0.8% most downloaded packages on CRAN. The data are based on the Posit CRAN mirror logs. There are approximately 150 million package downloads per month from the Posit CRAN mirror alone. Since none of the other CRAN mirrors provide statistics, it is impossible to know the total amount of package installations.
As a reference, the popular foreach, released in 2009, was among the top-0.8% most downloaded packages during the same period and it has 1,107 reverse package dependencies on CRAN. The number of users that download future has grown rapidly whereas the the same number has slowly decreased for the foreach package (Figure 1). Similarly, the number of reverse package dependencies on future appear to grow faster than for foreach (Figure 2).
Figure 2: Number of CRAN packages that depend on future, future.apply, furrr, and foreach over time since the first release of future in June 2015. Left: The package counts on the linear scale without foreach. Right: The same data on the logarithmic scale to fit also foreach. (Because historical data for reverse dependencies on Bioconductor are hard to track down, they are currently not reported in these graphs.)
Importantly, the comparison toward foreach is only done as a reference for the current demand for parallelization frameworks in R and to show the rapid uptake of the future framework since its release. It is not a competition because foreach can per design be used in companion with the future framework via doFuture. The choice between foreach with doFuture, future.apply, and furrr is a matter of preference of coding style - they all rely on futures for parallelization.