If you're choosing between RadarOpus and Similia in 2026, the short answer is: RadarOpus is the deepest traditional desktop reference library in homeopathy, and Similia is a cloud-native workspace built around modern AI. The right choice depends on whether you value an established desktop suite with a deep one-time-purchase library, or an AI-assisted browser workspace that ships five native AI features and a free forever tier.

Disclosure: I'm the founder of Similia. I've tried to be even-handed below — corrections welcome by email.

TL;DR — RadarOpus vs Similia at a glance

RadarOpus has been the dominant professional homeopathy desktop suite since 1982 and is published by Zeus Soft (branded as Archibel). It ships in five lifetime-license tiers ranging from $499.99 to $9,999.99, depending on how many repertories and materia medica titles you want. Similia is a cloud-based platform with a free forever tier and Pro plans starting at $19.99/month, built around five native AI features — semantic search across repertory and MM, Notes-to-Rubric, AI Case Analysis, live audio transcription, and AI Photo Analysis — plus complete cross-device case management.

Dimension	RadarOpus	Similia
Price	$499.99 – $9,999.99 lifetime (radaropus.us); payment plan from $99.99 down + $100/mo	Free forever + Pro from $19.99/mo (14-day trial)
Repertories	1 – 40 depending on package	7 classical (Free) + 7 premium (Pro), incl. Complete Repertory 2026
Materia medica	21 – 1,137 titles depending on package	12+ classical (Free) + Jan Scholten's full series on every Pro tier; 12+ modern total with add-ons
AI	Vithoulkas Expert System (rule-based) + thin GPT-style integration	Semantic search, Notes-to-Rubric, AI analysis, live audio, photo analysis
Case management	Local desktop, levels 1–4 by package	Complete, simple-to-use, cloud-synced across devices
Cloud / desktop	Native Windows + macOS desktop	Cloud-based; runs in any modern browser, any device
Best for	Practitioners who prefer a deep, traditional desktop suite and the RADAR/Synthesis lineage	Students, mobile-first, AI-curious — and busy expert practitioners

What is RadarOpus?

RadarOpus is a professional homeopathy desktop application developed by Zeus Soft (the company behind the Archibel brand), founded in 1989. Its lineage goes back to the original RADAR software released in 1987, making it the longest-running homeopathy software still actively distributed.

According to the Techjockey product listing, the current version is RadarOpus 2.2.16, with one year of automatic updates included after purchase. The software runs natively on Windows 7 through 10 and on macOS 10.12 (Sierra) and higher, with no Linux build advertised. RadarOpus is sold through the global Zeus Soft / Archibel network; current US prices are published openly on radaropus.us as five lifetime-license packages, and a payment plan is available from $99.99 down + $100/month.

What sets RadarOpus apart is the breadth of its bundled content: the marketing materials cite around 180,400 rubrics and over 1,077,000 remedy entries across the full library, plus integrated patient management (Levels 1–4), the Synthesis repertory family (Core, Treasure, Adonis), and the Vithoulkas Expert System for case differentiation. It's the de facto standard in many full-time clinics and remains the reference platform many post-graduate homeopathy programs train on.

What is Similia?

Similia is a modern, cloud-native homeopathy platform with a free-forever tier and four Pro editions. It runs in any modern browser on desktop, tablet, or phone — no installation, no separate mobile app to maintain. The free tier ships with seven classical repertories (Kent, Boericke, Boenninghausen's Therapeutic Pocketbook, Hering's Guiding Symptoms, Boger's Synoptic Key, Ward's and Roberts' "Sensations As If") plus 12+ classical materia medica titles (Kent, Boericke, Clarke, Allen's Keynotes, Hering, Boger, Lippe, Paterson and more), AI-powered semantic search across repertory and MM, and a complete, simple-to-use case management system.

Every Pro tier (Base, Murphy, Complete, Saine) unlocks the full AI suite (Notes-to-Rubric extraction, AI Case Analysis, live audio consultation transcription, AI Photo Analysis), Jan Scholten's full materia medica series (Elements, Lanthanides, Minerals, Mosses, Ferns, Qjure, Wonderful Plants — 7 modern MM books), Materia Medica Search, the Periodic Table, and unlimited cases. Up to seven premium repertories are available across the Pro ecosystem — pick the matching edition for Murphy's MetaRepertory (Pro Murphy), Complete Repertory 2026 (Pro Complete), or Saine Repertory 2025 (Pro Saine); Pro Murphy also bundles Murphy's Nature's MM 4th ed. Add Suggesta 2.1, Qrep5, Mangialavori 100 MM and other extensions as one-time add-ons, bringing the total available modern materia medica to 12+ titles. For full plan details and current prices, see the dedicated free homeopathic software page or the Similia pricing page.

Side-by-side comparison

Pricing

RadarOpus publishes USD pricing on radaropus.us as five lifetime packages, as of May 2026:

Student Practitioner — $499.99 (1 repertory, 21 materia medica)
Beginning Practitioner — $1,999.99 (19 repertories, 91 materia medica)
Everyday Practitioner — $4,299.99 (19 repertories, 713 materia medica)
Advanced Practitioner — $6,299.99 (20 repertories, 982 materia medica)
All-Inclusive Practitioner — $9,999.99 (40 repertories, 1,137 materia medica)

These are one-time purchases that include one year of updates. A payment plan is offered on radaropus.us/packages/ from $99.99 down + $100/month.

Similia publishes pricing on the Similia pricing page: Free forever, Pro Base $19.99/month, Pro Murphy and Pro Complete $29.99/month, Pro Saine $26.99/month, all with a 14-day free trial. Add-ons (Suggesta 2.1 at $299.99, Qrep5 at $99.99, etc.) extend the library without forcing an edition change.

The accurate way to read these two models: RadarOpus is a capital expenditure (you buy the library, updates included for year one only — further updates are paid extras), Similia is an operating expenditure (you subscribe to keep using it, but updates and AI improvements ship continuously and are always included). Similia Pro Base at $19.99/mo unlocks the full AI suite (5 features), Jan Scholten's full materia medica series, unlimited cases, the Periodic Table, and Materia Medica Search — on top of Free's 7 classical repertories and 12+ classical materia medica titles. Premium repertories come with picking the matching Pro edition (Murphy / Complete at $29.99/mo, Saine at $26.99/mo) or via paid add-ons.

Repertories

RadarOpus's All-Inclusive package (40 repertories) is the broadest commercial repertory bundle on the market, anchored by the Synthesis Adonis repertory and including specialty and historical works that are difficult to find elsewhere. The mid-tier packages center on the Synthesis Treasure (19 repertories), which is what most working practitioners actually use day-to-day.

Similia ships 14+ repertories across Free + Pro: 7 classical on the free tier (Kent, Boericke, Boenninghausen, Hering, Boger, Ward, Roberts) and 7 premium on Pro (Murphy's MetaRepertory, Complete Repertory 2026, Saine Repertory 2025, Suggesta 2.1, plus other extensions). The library is narrower than RadarOpus's All-Inclusive but covers the repertories most working practitioners actually use — and, importantly, every repertory is accessible from any device through AI semantic search rather than requiring you to remember repertory-specific terminology.

If your practice depends on rare 19th-century repertories (e.g., Knerr, Bell's Diarrhoea, Phatak in original form), RadarOpus has a real advantage. If your practice runs on Kent + Boenninghausen + Murphy + Complete, both tools cover what you need. For deeper context on the major repertories, see our guide to Murphy's vs Kent's vs Complete Repertory.

Materia medica

The Advanced Practitioner package of RadarOpus includes 982 materia medica titles, and the All-Inclusive package goes to 1,137 — a depth no other vendor matches. If you frequently quote older sources (Allen's Encyclopaedia, Hahnemann's Chronic Diseases, Hering's Guiding Symptoms in their full original form), RadarOpus puts them on your desktop.

Similia ships 12+ classical materia medica titles on Free (Kent, Boericke, Clarke, Allen's Keynotes, Boger, Hering's Guiding Symptoms, Lippe, Paterson and more). Every Pro edition bundles Jan Scholten's full Materia Medica series (Elements, Lanthanides, Minerals, Mosses, Ferns, Qjure, Wonderful Plants — 7 modern MM books); Pro Murphy also bundles Murphy's Nature's MM 4th ed. Suggesta 2.1, Mangialavori 100 MM, Qrep5 and other modern materia medica are available as paid add-ons, bringing the total available to 12+ modern titles. AI semantic search across the materia medica lets you search every loaded source at once in plain language — a feature RadarOpus doesn't ship.

For most clinical practice, both libraries are deep enough. RadarOpus wins decisively for historical or scholarly research where 19th-century primary sources matter; Similia wins on modern MM and on how fast you can find what you need.

AI

This is the section where the two products diverge most sharply, so it deserves a careful read.

RadarOpus integrates the Vithoulkas Expert System (a longstanding, rule-based statistical decision-support tool) and offers strong patient-management automation. More recently it has added a GPT-style integration for natural-language search — useful, but architecturally a thin wrapper around an external LLM rather than a native AI workflow. There is no semantic search across the full library, no live consultation transcription, no photo analysis, and no notes-to-rubric extraction in the core RadarOpus product.

Similia is built around AI from the ground up. The five AI features available are:

Semantic search across the repertory — accepts natural-language symptom descriptions ("a tight band squeezing my temples") and surfaces matching rubrics across every loaded repertory. No need to know which book uses "constriction" vs "pressing" vs "as if a band."
Semantic search across the materia medica — search every loaded MM source at once in plain language; cross-references and clinical pictures surface without manual book-flipping.
Notes-to-Rubric — paste consultation notes and let AI extract symptoms and propose matching rubrics for review.
AI Case Analysis — once a case is built, AI suggests differential remedy lines and flags symptoms that statistically discriminate the candidates.
Live audio transcription — capture a consultation in real time, get a structured transcript, and have symptoms auto-mapped to rubrics. Add AI Photo Analysis for tongue, skin, and lesion photos.

None of this replaces clinical judgement; it removes mechanical lookup time. If you've been frustrated by traditional repertory software's reliance on knowing the exact rubric phrasing in advance, this gap matters more than any feature spec sheet implies — and it's the reason busy expert practitioners adopt Similia even after a decade on RadarOpus.

Patient case management

RadarOpus includes a multi-level patient management system (Levels 1–4 across packages), with HIPAA and GDPR-compliant privacy implementations advertised on the U.S. site. Cases live on your local machine; cloud sync is not the primary model.

Similia ships a complete, simple-to-use case management system that's cloud-first by design: cases live in your Similia account, sync across all your devices, and remain accessible from any browser. The interface is built so a new student can record a first case end-to-end without training, while still giving experienced practitioners full control over rubric weighting, history, follow-ups, and analysis. Encryption-in-transit and at-rest, GDPR compliance, and HIPAA-ready handling are documented in our compliance guide. If you switch from a desktop to a tablet mid-consultation, your case is just there.

Platform & devices

RadarOpus runs natively on Windows 7+ and macOS 10.12+; no Linux build, and the dedicated mobile experience is limited compared to the desktop product.

Similia runs in any modern browser on Windows, macOS, Linux, iOS, Android, and ChromeOS. There is nothing to install, no driver to manage, no platform-specific bug surface.

Support & community

RadarOpus has decades of training resources, regional dealers in most countries, multiple post-graduate programs that train on the software, and an active user community. If you want hands-on classroom training, this is meaningful.

Similia provides email support, an evolving knowledge base, and direct contact with the founding team. The community is younger but growing, particularly among practitioners who started homeopathy after 2020. If you're also weighing Hompath, our Hompath Zomeo vs Similia comparison covers another angle.

Updates & roadmap

RadarOpus releases major versions roughly every 12–18 months, with one year of free updates included in each license. Content updates (new repertory editions, new materia medica) are distributed on a similar cadence.

Similia ships continuously — repertory updates, AI improvements, and UI polish land in production weekly without a manual upgrade step. Subscribers always get the latest version.

When RadarOpus is the better choice

Be honest about who wins where. RadarOpus is the better choice in at least these scenarios:

You run a high-volume specialist clinic that depends on rare repertories or 19th-century materia medica primary sources. The All-Inclusive package's 40-repertory, 1,137-MM library is unmatched.
You strongly prefer a one-time purchase and an established desktop suite. A Beginning Practitioner license at $1,999.99 lasts indefinitely (with no further updates after year one); for practitioners who like the RADAR/Synthesis lineage and a permanent on-disk reference library, that's a fair trade.
You're being trained in a program that uses RadarOpus as the teaching tool. Continuity with your school's case files and notation is worth a lot in the early years.
You work entirely offline. RadarOpus is a true desktop application; nothing depends on connectivity.

When Similia is the better choice

You want native AI tools — five of them. Semantic search across repertory and materia medica, Notes-to-Rubric extraction, AI Case Analysis, live audio transcription, and AI Photo Analysis. RadarOpus doesn't ship any of these as native features; the Vithoulkas Expert System is rule-based and the GPT-style search is a thin wrapper.
You're a busy expert practitioner. Live transcription + auto-mapping saves 10–15 min per consultation; Photo Analysis turns a tongue picture into rubrics in seconds. The volume payoff scales with caseload.
You're a student or new practitioner. Similia's free tier gives you Kent, Boericke, Boenninghausen, Hering, Boger, Ward, Roberts, plus 12+ classical materia medica titles plus AI semantic search — perpetually. RadarOpus's Student Practitioner tier at $499.99 still gates the full feature set.
You work across devices or on the move. Doing a home visit on an iPad, then continuing on a laptop in the office, is native to Similia and clunky on a desktop suite.
You're cost-sensitive in years 1–3. A Pro Base subscription at $19.99/month is $240/year vs $1,999.99 upfront for the Beginning Practitioner package — and you can downgrade or cancel any month.
You use Linux or ChromeOS. Similia just works in the browser; RadarOpus does not officially support either.

If you're already comparing more options, our roundup post — Best Homeopathic Software 2026 — covers Hompath Zomeo, Complete Dynamics, and Vithoulkas Compass alongside both of these.

FAQ

Is RadarOpus free?

No. As of May 2026, RadarOpus does not offer a free tier or a free trial. The Student Practitioner package is the lowest entry point at $499.99 (one-time, lifetime license). A demo can be requested from regional dealers. By contrast, Similia's free plan never expires.

Can I switch from RadarOpus to Similia?

Yes. There is no official case-import path, but Similia's case template structure (chief complaint, modalities, observations, repertorisation, prescription, follow-up) maps cleanly to RadarOpus. Most practitioners migrate active cases by hand and archive the old RadarOpus database for reference. Existing RadarOpus owners often run both for the first 6–12 months: RadarOpus for deep-library lookups, Similia for daily consultations and AI-assisted notes. If you're considering it, see also our Hompath Zomeo vs Similia comparison for a sense of how Similia handles other migrations.

Does RadarOpus have AI features?

RadarOpus integrates the Vithoulkas Expert System (rule-based, longstanding) and a thin GPT-style integration for natural-language queries. It is not built around AI workflows — there is no semantic search across the full library, no live consultation transcription, no photo analysis, and no notes-to-rubric extraction. Similia ships semantic search across both repertory and materia medica, Notes-to-Rubric, AI Case Analysis, live audio transcription, and AI Photo Analysis as native features.

Which has more repertories?

RadarOpus's top-tier All-Inclusive package includes 40 repertories — the largest commercial bundle. Similia includes 14+ across its tiers. For day-to-day clinical practice, both cover Kent, Boenninghausen, Murphy, and Complete; for rare or historical works, RadarOpus wins.

Which is better for students?

Similia, in most cases. The free tier gives full access to seven classical repertories, 12+ classical materia medica titles, AI semantic search, and a complete case management system at zero cost — invaluable while you're still discovering which repertory style you prefer. RadarOpus's $499.99 Student Practitioner tier is reasonable but still a meaningful investment for a learner.

Verdict

RadarOpus and Similia aren't really competing for the same buyer. RadarOpus is the right answer if you want the deepest commercial reference library in homeopathy delivered as a permanent desktop investment in the established RADAR/Synthesis tradition. Similia is the right answer for the much larger group of practitioners — students, mobile-first practitioners, AI-curious clinicians, and busy expert practitioners — who want a free forever starting point that scales into a modern AI-assisted workflow, syncs across devices, and grows with your practice rather than locking you into a particular machine.

Many established practitioners use both — RadarOpus for archival depth, Similia for daily AI-assisted consultations. If you're starting out, start with Similia's free plan. You can always add RadarOpus later if you find your practice demands library depth Similia can't match. And if you're still weighing the field, the best homeopathic software roundup walks through five tools side by side.

RadarOpus vs Similia 2026 — Honest Comparison (Pricing, Features, Verdict)