zarr-python
Zarr's package split keeps producing standalone tools: a server, now a lazy indexer.
Comparison · DevOps
htmltools vs promises
A side-by-side editorial comparison of htmltools and promises — release velocity, themes, recent moves, and the top alternatives to consider.
Shared themes:shiny
htmltools vs promises: at a glance
What is htmltools?
htmltools spends three releases walking back its own fill-layout opinions
htmltools generates the HTML that Shiny, bslib and R Markdown emit. Recent releases are dominated by one project - the fill and fillable layout system that powers bslib cards - being tuned release after release, surrounded by fixes for whatever testthat or R-devel changed underneath.
What is promises?
promises drops R6 for plain environments and wires async work into OpenTelemetry
promises supplies the async primitives behind Shiny and plumber. After years of small domain and future() fixes, the last two releases changed both what a promise costs and what it can report: 1.4.0 corrected nested domain ordering and added the first OpenTelemetry integration, and 1.5.0 replaced the R6 promise class with a classed environment while stabilizing the tracing API.
htmltools vs promises: editorial side-by-side
htmltools
0.0DEVOPS
htmltools spends three releases walking back its own fill-layout opinions
◆ Current state
htmltools generates the HTML that Shiny, bslib and R Markdown emit. Recent releases are dominated by one project - the fill and fillable layout system that powers bslib cards - being tuned release after release, surrounded by fixes for whatever testthat or R-devel changed underneath.
◆ Where it's heading
The fill work is converging rather than expanding: 0.5.6 stopped forcing overflow on fillable containers, 0.5.7 stopped forcing full width on fill items, and 0.5.8 lowered the CSS's precedence by moving it into a named cascade layer. Each step removes an opinion that broke someone's layout. The two most recent releases add nothing at all beyond test compatibility.
◆ Prediction
With the fill CSS now scoped to its own cascade layer, expect fewer layout corrections and a continued pattern of small releases driven by testthat and R-devel rather than new API.
promises
0.0DEVOPS
promises drops R6 for plain environments and wires async work into OpenTelemetry
◆ Current state
promises supplies the async primitives behind Shiny and plumber. After years of small domain and future() fixes, the last two releases changed both what a promise costs and what it can report: 1.4.0 corrected nested domain ordering and added the first OpenTelemetry integration, and 1.5.0 replaced the R6 promise class with a classed environment while stabilizing the tracing API.
◆ Where it's heading
Two things are being fixed at once. Promise domains - the mechanism that carries context across async boundaries - have been the source of nearly every bug in this window, and they are now being used deliberately as the vehicle for tracing rather than just for error handling. Meanwhile the object itself is being made cheap enough to create in volume.
◆ Prediction
Expect the OpenTelemetry surface to lose its experimental label and pick up the same span coverage Shiny would need end to end; the deprecated ospan function names should be removed in a following release.
Alternatives to htmltools and promises
Other DevOps 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 htmltools or promises.
ellipsis
ellipsis' checks live in rlang now; the package is a compatibility shim.
clock
clock is turning calendar conventions lubridate hard-coded into parameterized types.
httpuv
httpuv ships almost nothing, which is what you want from the web server under Shiny
withr
withr rebuilt defer() on base R's own on.exit(), and got much faster for it
xml2
xml2 relicensed to MIT, then moved its hot accessors from S3 into C
See all htmltools alternatives → · See all promises alternatives →
Recent activity from htmltools and promises
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 8mo agohtmltoolsTest fix for testthat 3.3.0
- 8mo agohtmltoolscapturePlot() examples run only interactively
- 9mo agopromisesOpenTelemetry spans across async work; R6 dropped for environments ⚡
- 9mo agopromisesNested promise domains fixed; then() gains a tee argument
- 1y agopromisesRealigns future object creation with the future package
- 1y agopromisesFixes stack overflow on long promise chains
- 1y agopromisesFixes domains forgotten inside nested handlers
- 2y agohtmltoolsFill CSS moves into its own cascade layer
- 2y agohtmltoolssave_html() becomes generic; css() passes CSS variables through
- 2y agohtmltoolstagQuery() no longer errors traversing NULL on r-devel
- 3y agohtmltoolsFillable containers stop forcing overflow, respect intrinsic size
- 3y agopromisesfuture_promise() returns early when workers are exhausted
Frequently asked questions
What is the difference between htmltools and promises?
Both compete on the same themes — shiny — within DevOps. htmltools and promises are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is htmltools better than promises?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. htmltools and promises are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). For your specific use case, the alternatives sections above list other DevOps products to evaluate alongside.
What are the best alternatives to htmltools?
Top htmltools alternatives in DevOps are ranked by recent ship velocity. Browse the "htmltools alternatives" section above for the current picks, or visit /alternatives/htmltools for the full list with editorial commentary on each.
What are the best alternatives to promises?
Top promises alternatives in DevOps are ranked by recent ship velocity. Browse the "promises alternatives" section above for the current picks, or visit /alternatives/promises for the full list with editorial commentary on each.