servr
servr keeps growing from a static file server into a general-purpose R web server.
Comparison · Infra & APIs
Dragonfly vs RSelenium
A side-by-side editorial comparison of Dragonfly and RSelenium — release velocity, themes, recent moves, and the top alternatives to consider.
Dragonfly vs RSelenium: at a glance
What is Dragonfly?
Dragonfly is spending its releases on correctness debt, not features.
The last two months are almost entirely correctness work: a pub/sub ordering bug that silently discarded queued messages on unsubscribe, a multi-key PFCOUNT that read sixteen wrong registers, an uninitialized pointer in the sparse HyperLogLog promote path, and now cluster FLUSHSLOTS that was not journaled inside its own flush transaction. The one structural move is the resync of the forked hyperloglog.c against valkey upstream, which cut divergence from 2,139 lines to 767 and pulled in a CVE fix plus AVX2 and NEON merge kernels. New user-facing options are rare; the list compression tuning flags are the exception.
What is RSelenium?
RSelenium's only release in eight years touched documentation and CI, nothing else.
1.7.10, published February 2026, contains documentation updates, a move from Travis CI to GitHub Actions, and CRAN note fixes — no functional change at all, and it is the first release since September 2018. The releases before it are equally quiet: a dummy argument in `executeScript`, `phantom()` made defunct, and credential-exposure and driver-startup fixes. The last real capability change in the window is `rsDriver()` arriving in 1.6.4, which replaced the defunct `checkForServer` and `startServer` helpers.
Dragonfly vs RSelenium: editorial side-by-side
Dragonfly
5.0INFRA · APIS
Dragonfly is spending its releases on correctness debt, not features.
◆ Current state
The last two months are almost entirely correctness work: a pub/sub ordering bug that silently discarded queued messages on unsubscribe, a multi-key PFCOUNT that read sixteen wrong registers, an uninitialized pointer in the sparse HyperLogLog promote path, and now cluster FLUSHSLOTS that was not journaled inside its own flush transaction. The one structural move is the resync of the forked hyperloglog.c against valkey upstream, which cut divergence from 2,139 lines to 767 and pulled in a CVE fix plus AVX2 and NEON merge kernels. New user-facing options are rare; the list compression tuning flags are the exception.
◆ Where it's heading
Two threads run in parallel. One reduces the cost of carrying a Redis fork by re-syncing individual files against valkey and leaving provenance notes so the next sync is cheap. The other hardens the V2 IO loop while the V1 path still takes the fixes — several commits explicitly defer the V2 half of a fix to a later change, so the two loops are not at parity. Cluster correctness around slot migration and journaling is the newest front.
◆ Prediction
The deferred V2 IO-loop fixes are the obvious next commits, and more forked Redis files are likely to get the same upstream resync treatment now that the pattern and its accounting are established.
RSelenium
0.0INFRA · APIS
RSelenium's only release in eight years touched documentation and CI, nothing else.
◆ Current state
1.7.10, published February 2026, contains documentation updates, a move from Travis CI to GitHub Actions, and CRAN note fixes — no functional change at all, and it is the first release since September 2018. The releases before it are equally quiet: a dummy argument in `executeScript`, `phantom()` made defunct, and credential-exposure and driver-startup fixes. The last real capability change in the window is `rsDriver()` arriving in 1.6.4, which replaced the defunct `checkForServer` and `startServer` helpers.
◆ Where it's heading
This is a package being kept installable rather than developed. The 2016-2018 era did the architectural work — moving process management out to wdman, recommending Docker for running a Selenium server, retiring PhantomJS — and nothing since has revisited it. That leaves RSelenium sitting on the older WebDriver arrangement while the browser-automation landscape has moved on.
◆ Prediction
Further releases, if any, are likely to be CRAN-compliance rather than feature work; the entries give no indication of active development resuming.
Alternatives to Dragonfly and RSelenium
Other Infra & APIs products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Dragonfly or RSelenium.
Rhino
Rhino's release line runs on release candidates, and 1.12 makes room for coding agents.
Windmill
Windmill is dismantling the paywall between itself and the data stack
Resend
Resend is wiring itself into every agent runtime it can reach, one standard at a time
vdiffr
vdiffr finished its job in 2021 and has been tracking compilers ever since.
rsconnect
The deployment client is being rebuilt around credentials it never has to store.
See all Dragonfly alternatives → · See all RSelenium alternatives →
Recent activity from Dragonfly and RSelenium
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 1d agoDragonflyBackported memory-accounting fix; FLUSHSLOTS journaled in-transaction
- 14d agoDragonflyi1.39.11: chore(hll): sync hyperloglog.c with valkey upstream (#7961)
- 20d agoDragonflyFix mutable cross-thread access on shared reply builder
- 22d agoDragonflyi1.39.9: fix(facade): preserve pub/sub order on unsubscribe (v1 IO loop) (#7909)
- 1mo agoDragonflyi1.39.6: test: skip V2-only pause tests under V1 (#7822)
- 1mo agoDragonflyi1.39.4: Add list compression tuning flags (#7762)
- 5mo agoRSeleniumRSelenium 1.7.10 updates docs and moves CI to GitHub Actions
- 7y agoRSeleniumRSelenium 1.7.4 retires phantom() and fixes rsDriver
- 9y agoRSeleniumRSelenium 1.7.1 fixes rsDriver argument passing
- 9y agoRSeleniumRSelenium 1.7.0 makes rsDriver the entry point
- 9y agoRSeleniumRSelenium 1.6.2 adds selectTag, moves to httr
- 9y agoRSeleniumRSelenium 1.5.0 fixes executeScript and RStudio completion
Frequently asked questions
What is the difference between Dragonfly and RSelenium?
They serve adjacent needs but don't currently overlap on shipped themes. Dragonfly is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is Dragonfly better than RSelenium?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Dragonfly is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Infra & APIs products to evaluate alongside.
What are the best alternatives to Dragonfly?
Top Dragonfly alternatives in Infra & APIs are ranked by recent ship velocity. Browse the "Dragonfly alternatives" section above for the current picks, or visit /alternatives/dragonfly for the full list with editorial commentary on each.
What are the best alternatives to RSelenium?
Top RSelenium alternatives in Infra & APIs are ranked by recent ship velocity. Browse the "RSelenium alternatives" section above for the current picks, or visit /alternatives/rselenium for the full list with editorial commentary on each.