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fossilsim vs vellum

A side-by-side editorial comparison of fossilsim and vellum — release velocity, themes, recent moves, and the top alternatives to consider.

fossilsim vs vellum: at a glance

Featurefossilsimvellum
SectorAnalyticsAnalytics
Velocity score0.05.0
Sparks · 30d00
Top themesphylogenetics, simulation, trait-evolution, birth-death-modelsr-graphics, rendering-engine, linting, accessibility
Last editorial update1h ago7h ago
WebsiteVisit →Visit →

What is fossilsim?

A fossil-record simulator that quietly grew a trait-evolution engine.

FossilSim is a mature R package for simulating fossil records on phylogenetic trees, and its release cadence reflects that: long gaps punctuated by a single capability addition. The last four releases span three years, with the most recent being a compatibility sync to its companion Shiny front-end rather than new functionality. The core simulation surface has been stable since 2022.

Read the full fossilsim trajectory →

What is vellum?

vellum's bugs are now found by using it, not testing it — the downstream grammar is doing the QA.

The rendering engine shipped nine releases in the two weeks around the end of July, six of them on a single day. Almost every entry is a correctness fix in a capability that worked when drawn and failed when measured, or worked in isolation and failed in composition. The release notes are unusually forensic: each one states the mechanism, the observable symptom, and why the fix mirrors the draw path rather than reimplementing it.

Read the full vellum trajectory →

fossilsim vs vellum: editorial side-by-side

F
fossilsim
ANALYTICS
0.0

A fossil-record simulator that quietly grew a trait-evolution engine.

◆ Current state

FossilSim is a mature R package for simulating fossil records on phylogenetic trees, and its release cadence reflects that: long gaps punctuated by a single capability addition. The last four releases span three years, with the most recent being a compatibility sync to its companion Shiny front-end rather than new functionality. The core simulation surface has been stable since 2022.

◆ Where it's heading

The arc runs from sampling mechanics toward simulating what the organisms actually were. Version 2.2.0 taught the package to handle occurrence data for occurrence birth-death models; 2.3.0 then added trait simulation under Mk, BM and OU, which is a different kind of output than fossil ages. Since then the work has been maintenance and keeping the FossilSimShiny GUI in step, suggesting the authors consider the current model set feature-complete.

◆ Prediction

The pairing of the 2.3.3 release with a FossilSimShiny version bump points to the GUI, not the library, as where the next visible work lands. The entries do not show enough activity to predict a specific new model family.

V
vellum
ANALYTICS
5.0

vellum's bugs are now found by using it, not testing it — the downstream grammar is doing the QA.

◆ Current state

The rendering engine shipped nine releases in the two weeks around the end of July, six of them on a single day. Almost every entry is a correctness fix in a capability that worked when drawn and failed when measured, or worked in isolation and failed in composition. The release notes are unusually forensic: each one states the mechanism, the observable symptom, and why the fix mirrors the draw path rather than reimplementing it.

◆ Where it's heading

The pivotal detail is stated outright in 0.6.3 — the first bug in the series found by using the engine from vellumplot rather than testing it in isolation. Every release since names the downstream as the source: the contrast rule's false positives, the lint rules that fired on all five sample plots, the keyed roundrect batch. A rendering engine with a real grammar built on top of it is now getting the integration coverage that unit tests structurally cannot provide, and the fixes are converging on one theme: the measurement path and the draw path must not drift.

◆ Prediction

Expect the release rate to fall as the vellumplot integration surface is exhausted, with remaining work concentrated in the lint rule set now that it is meant to gate builds rather than just inform.

Alternatives to fossilsim and vellum

Other Analytics 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 fossilsim or vellum.

See all fossilsim alternatives → · See all vellum alternatives →

Recent activity from fossilsim and vellum

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 11d agovellumLinter grows to 20 rules and stops firing on every plot
  2. 13d agovellumAnimated SVGs no longer blink once and vanish or play in reverse
  3. 14d agovellumPick table now reports device pixels instead of two coordinate systems
  4. 15d agovellumContrast rule stops flagging every plot; gridlines become PDF artifacts
  5. 15d agovellumgrobwidth and grobheight now measure wrapped text, not the unwrapped line
  6. 15d agovellumKeyed roundrect becomes a real batch after downstream integration exposes it
  7. 2y agofossilsimCompatibility bump for FossilSimShiny 1.1.2
  8. 4y agofossilsimBug fixes and documentation cleanup
  9. 4y agofossilsimTrait simulation arrives: Mk, BM and OU models
  10. 5y agofossilsimOccurrence handling for the occurrence birth-death model

Frequently asked questions

What is the difference between fossilsim and vellum?

They serve adjacent needs but don't currently overlap on shipped themes. vellum 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 fossilsim better than vellum?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. vellum 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 Analytics products to evaluate alongside.

What are the best alternatives to fossilsim?

Top fossilsim alternatives in Analytics are ranked by recent ship velocity. Browse the "fossilsim alternatives" section above for the current picks, or visit /alternatives/fossilsim-r for the full list with editorial commentary on each.

What are the best alternatives to vellum?

Top vellum alternatives in Analytics are ranked by recent ship velocity. Browse the "vellum alternatives" section above for the current picks, or visit /alternatives/vellum-r for the full list with editorial commentary on each.