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utility libraries, ranked by real usage_

As of 4 November 2026, RxJS leads utility libraries with 434 companies naming it in job postings, ahead of Pydantic at 366.

As of 4 November 2026 · refreshed daily · counts move as websites, DNS and career sites are re-read.

Leader
RxJS · 434
Runner-up
Pydantic · 366
Most hiring, 90 days
RxJS
Highest postings per company
Kotlin Flow
Catalogue
T-1.0.1-prov
4,049companies across the category
11%of them on RxJS
8,853postings naming a utility librarie in 90 days
40tools with enough evidence to rank
02 — Ranking

Every utility librarie we can measure

Companies naming the tool, and postings naming it in the last 90 days. Bars are relative to the leader.

#ToolCompaniescompaniesPostings, 90 dayspostingsper company
1
RxJSReactiveX
434
1,0522.4
2
PydanticPydantic
366
8372.3
3
asyncioPython Software Foundation
228
5682.5
4
FFmpegFFmpeg
197
3481.8
5
GStreamerGStreamer
194
3261.7
6
GSAPGreenSock
172
3151.8
7
JinjaPallets
172
2941.7
8
HiltGoogle
168
2601.5
9
DaggerGoogle
165
5103.1
10
RetrofitSquare
165
2371.4
11
BoostBoost
153
3302.2
12
RxJavaReactiveX
133
1971.5
13
DPDKLinux Foundation
122
4123.4
14
Kotlin CoroutinesJetBrains
118
4283.6
15
ZodZod contributors
115
3913.4
16
AxiosAxios contributors
85
2883.4
17
Beautiful Soup
79
831.1
18
Boto3Amazon Web Services
79
1692.1
19
OkHttpSquare
78
1331.7
20
ScrapyZyte
74
841.1
21
Project ReactorVMware
70
1742.5
22
Socket.IO
69
991.4
23
TokioTokio contributors
67
1422.1
24
RequestsPython Software Foundation
63
1171.9
25
Video4Linux2Linux Foundation
63
1091.7
26
Apache Log4jApache Software Foundation
60
1081.8
27
PillowPython Software Foundation
49
921.9
28
Prototype.jsPrototype Core Team
42
561.3
29
RestSharp
41
621.5
30
JacksonFasterXML
31
672.2
31
aiohttpaio-libs
28
401.4
32
Project LombokProject Lombok
28
602.1
33
EffectEffectful Technologies
27
321.2
34
Autofac
21
371.8
35
LodashOpenJS Foundation
20
221.1
36
MoshiSquare
17
231.4
37
Netflix HystrixNetflix
15
372.5
38
Kotlin FlowJetBrains
14
26318.8
39
MustacheMustache project
14
241.7
40
ZIO
13
272.1
03 — Head to head

Compare two tools

Same data, two columns: who chooses which by size, industry and country.

RxJS vs Pydantic434 · 366RxJS vs asyncio434 · 228RxJS vs FFmpeg434 · 197RxJS vs GStreamer434 · 194RxJS vs GSAP434 · 172Pydantic vs asyncio366 · 228Pydantic vs FFmpeg366 · 197Pydantic vs GStreamer366 · 194Pydantic vs GSAP366 · 172asyncio vs FFmpeg228 · 197asyncio vs GStreamer228 · 194asyncio vs GSAP228 · 172FFmpeg vs GStreamer197 · 194FFmpeg vs GSAP197 · 172GStreamer vs GSAP194 · 172
Cite this

Quote the sentence with the date and the link. The numbers change daily; the link always shows the current ones.

RxJS leads utility libraries with 434 companies naming it in job postings, ahead of Pydantic at 366. (Breaknorm, 4 November 2026, https://breaknorm.co/tools/category/utility-libraries)
How we know

Read from the source, not self-reported

Every number on this page can be traced to a page we crawled or a posting we read. Full methodology →

  • CatalogueBreaknorm technology catalogue T-1.0.1-prov: 6,296 tools with vendor and category, editions folded into their parent.
  • CompaniesCompanies whose own postings name the tool as the team's system, any confidence. Candidate wish-lists excluded.
  • 90-day postingsOpen postings first seen or posted in the last 90 days that name the tool.
  • Not countedTools used by teams that do not post jobs, and companies without a career site we can read.
FAQ

utility libraries: questions

How is this ranking made?

By the number of companies whose own job postings name the tool as the team's system, from the Breaknorm technology catalogue (version T-1.0.1-prov). No vendor paid for a position and no editor chose the order.

Why is this different from review-site rankings?

Review sites rank by reviews collected. This ranks by companies hiring people to work in the tool, which is closer to seats in use. It under-counts tools used by teams that rarely post jobs.

What about product editions?

Editions and sub-products () are counted under the parent so no company is counted twice.

Can I get the companies behind a number?

Yes: click a tool, see the first 20, and sign up for the full list with verified e-mails. Counting is free.

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