Infisical is a platform that helps companies securely store and share sensitive credentials — like API keys, passwords, and configuration settings — across their teams and systems, while preventing those secrets from accidentally leaking into the wrong hands. Think of it as a secure, shared vault that keeps sensitive business information organized and protected, similar to how a password manager works but designed for entire engineering organizations.
Why it matters: With nearly 25,000 stars on GitHub and a growing open-source community, Infisical is gaining serious traction in a market where enterprises spend heavily on tools like HashiCorp Vault — meaning there's real commercial opportunity in offering a developer-friendly, open-source alternative. For founders and investors, this represents a classic open-source-led growth strategy in the high-stakes security space, where a single data breach can cost companies millions and make compliance-conscious buyers eager to adopt proven solutions.
This is a massive, freely available library of cybersecurity learning materials, tools, and guides covering topics like ethical hacking (legally testing systems for weaknesses), digital investigation techniques, and AI-related security risks, all curated by a well-known security expert. Think of it as a comprehensive textbook and toolkit rolled into one, used by security professionals to learn how attackers think so they can better defend against them.
Why it matters: With over 25,000 people starring this repository, it signals enormous market demand for cybersecurity education and tooling — a space growing rapidly as AI introduces new attack surfaces and data breach costs continue to rise. For PMs and founders, this highlights a real opportunity in security training products, vulnerability management tools, or AI safety features, and serves as a benchmark for what security-conscious users and teams actually need.
Jupyter Notebook★ 25.1k⑂ 4.8k👥 38Security KeePassXC is a free, open-source password manager that lets users securely store all their passwords, usernames, and sensitive information in an encrypted file that lives on their own device rather than in someone else's cloud. It works on Windows, Mac, and Linux, and includes features like browser integration, two-factor authentication support, and a built-in password generator.
Why it matters: With nearly 26,000 stars and 382 contributors, KeePassXC represents a significant market signal that a large segment of privacy-conscious users actively reject subscription-based password managers like LastPass or 1Password in favor of tools they fully control — a trend worth understanding for any product competing in the identity or security space. For founders and PMs, this project highlights the growing demand for offline-first, privacy-focused alternatives to SaaS security tools, especially as high-profile data breaches erode consumer trust in cloud-stored credentials.
Gitleaks is a security scanning tool that automatically searches through code repositories to find accidentally exposed sensitive information — like passwords, API keys, and access tokens — before they become a problem. It can be set up to run automatically every time a developer saves new code, acting like a safety net that catches credential leaks before they ever reach the internet.
Why it matters: Exposed API keys and credentials are one of the most common causes of costly data breaches, and even a single leaked secret can compromise an entire product or customer database. With nearly 25,000 stars on GitHub and broad adoption in developer workflows, Gitleaks represents a growing market expectation that security must be built into the development process from day one — making it a key signal for any company assessing their security posture or building developer-facing products.
osquery lets you investigate everything happening on a computer — running programs, network connections, user activity, and more — by asking questions in plain SQL, the same simple query language used to look up data in spreadsheets and databases. Think of it as turning your operating system into a searchable database, so security and IT teams can instantly answer questions like 'which programs are currently running and connecting to the internet?' without writing complex code.
Why it matters: With 23,000+ stars and nearly 400 contributors, osquery has become a foundational tool for enterprise security monitoring, meaning any company building security, IT management, or compliance products should understand it as a key part of the ecosystem their customers already use. Its open-source nature and broad adoption create a platform opportunity — startups and vendors who build on top of osquery can reach security teams already familiar with it, reducing sales friction and accelerating enterprise adoption.
Authelia is a free, open-source security gateway that lets users log in once to access multiple internal apps, while also requiring a second verification step (like a phone notification or hardware key) to confirm their identity. It acts as a central login portal that sits in front of your web applications and decides who gets access and who doesn't.
Why it matters: As data breaches and unauthorized access become increasingly costly, teams that build their own products need a proven, battle-tested login and access system rather than building one from scratch — Authelia, with nearly 27,000 stars and an official OpenID certification, signals serious market trust and adoption. For founders and PMs, this represents a strong build-vs-buy reference point: a self-hosted alternative to paid identity providers like Okta or Auth0, which is especially attractive for cost-conscious teams or those with strict data privacy requirements.
OWASP Cheat Sheet Series is a free, community-maintained library of straightforward security guides that help software teams build safer applications — think of it as a collection of expert-written playbooks covering topics like safe login systems, protecting user data, and preventing common attacks. It's maintained by the Open Worldwide Application Security Project (OWASP), a globally recognized nonprofit focused on improving software security standards.
Why it matters: With data breaches and security incidents making headlines constantly, having your engineering team follow industry-standard security practices is both a competitive advantage and a risk management necessity — and this free resource is one of the most widely trusted references in the field. For PMs and founders, it signals whether your team is building on a credible security foundation, which matters increasingly to enterprise buyers, regulators, and investors evaluating your product's trustworthiness.
TruffleHog scans code repositories and other digital sources to find exposed passwords, API keys, and other sensitive login credentials that should never have been made public. It goes beyond just finding these secrets — it also verifies whether they are still active and exploitable, helping teams understand the real risk they face.
Why it matters: A single leaked API key or database password can lead to a costly data breach, regulatory fines, or loss of customer trust — TruffleHog helps companies catch these mistakes before attackers do. With 24,600 stars and strong community adoption, this tool reflects a fast-growing market need as security becomes a non-negotiable part of any software product strategy.
Web-Check is a free tool that lets you instantly look up detailed background information on any website — including who owns it, where it's hosted, its security setup, and potential vulnerabilities — all from a single search. Think of it like a background check service for websites, pulling together dozens of data points that would otherwise require multiple separate tools to find.
Why it matters: With over 32,000 stars on GitHub, this tool has massive organic adoption, signaling strong market demand for simplified website intelligence and competitive research capabilities. For product teams and founders, it highlights an opportunity in the 'trust and transparency' space — users and businesses increasingly want to quickly vet websites before partnering, investing, or engaging with them.
Mitmproxy is a tool that lets developers and security researchers intercept and inspect the web traffic flowing between apps and the internet, similar to reading letters before they're delivered. It works like a controlled middleman that can capture, pause, modify, and replay any web requests or responses in real time.
Why it matters: With over 42,000 stars on GitHub, this widely-adopted tool signals strong demand for visibility into how apps communicate with servers — a critical concern as privacy regulations tighten and API-driven products grow more complex. For PMs and founders, it highlights the market need for traffic inspection and security testing tools, especially as companies face increasing scrutiny over data handling and third-party integrations.
Nuclei is an open-source security scanning tool that automatically checks your websites, apps, and cloud systems for known vulnerabilities and weaknesses before attackers can exploit them. It uses a community-contributed library of over thousands of threat scenarios to test your products against real-world attack patterns, helping teams catch security holes early.
Why it matters: With 27,000+ stars and 215 contributors, Nuclei represents a widely trusted standard in the security community, meaning teams that adopt it benefit from collective intelligence about emerging threats rather than relying solely on expensive proprietary tools. For product and engineering leaders, integrating this into the development pipeline shifts security from a costly last-minute audit into a continuous, automated safety net — reducing breach risk and potential regulatory liability.
OpenZeppelin Contracts is a library of pre-built, battle-tested building blocks that developers use to create smart contracts — self-executing agreements that run on blockchain networks like Ethereum. Think of it as a set of trusted, reusable Lego pieces that handle common functionality like digital token creation and access controls, so teams don't have to build everything from scratch.
Why it matters: With nearly 27,000 stars and over 12,000 forks, this is one of the most widely adopted foundations in the blockchain development ecosystem, meaning a huge portion of crypto products and Web3 startups are built on top of it. For founders and investors, a product team using OpenZeppelin signals they're following industry security best practices rather than rolling their own untested code — which significantly reduces the risk of costly hacks or vulnerabilities.
Radare2 is a powerful, free toolkit that lets security researchers and engineers take apart software programs to understand exactly how they work — even without access to the original source code. Think of it as an X-ray machine for software, allowing experts to inspect, analyze, and uncover hidden behaviors in applications, files, or potentially malicious programs.
Why it matters: With cybersecurity threats and software vulnerabilities costing businesses billions annually, tools like Radare2 are critical for teams conducting security audits, vetting third-party software, or investigating breaches — and its open-source nature means it's widely adopted across enterprise security teams and researchers worldwide. For founders and investors, the 23,000+ stars and nearly 350 contributors signal this is a foundational tool in the security ecosystem, making it highly relevant to any product strategy touching cybersecurity, compliance, or software integrity.
Trivy is a security scanning tool that automatically checks software, containers, and cloud infrastructure for known vulnerabilities, exposed secrets, and configuration mistakes before they become problems. Think of it as a comprehensive safety inspector that reviews everything your engineering team ships — from the apps themselves to the environments they run in — and flags risks in one place.
Why it matters: As regulators and enterprise buyers increasingly demand proof of software security practices, having automated scanning built into the development process is becoming a baseline expectation rather than a nice-to-have. With over 31,000 GitHub stars and nearly 3,000 forks, Trivy's wide adoption signals it has become a de facto standard in this space, meaning teams that don't use something like it face growing compliance, liability, and sales cycle risks.
Sniffnet is a free, easy-to-use desktop application that lets you see exactly what internet traffic is going in and out of your computer in real time, displayed in a clean visual interface. It works on Windows, Mac, and Linux, and is available in over 20 languages, making network visibility accessible to virtually anyone regardless of technical background.
Why it matters: With over 32,000 GitHub stars, Sniffnet signals massive demand for privacy and network transparency tools that don't require specialized expertise — a market gap that commercial products like Little Snitch or enterprise firewalls haven't fully addressed for everyday users. For founders and investors, this level of organic traction points to a viable consumer or SMB security product opportunity, particularly as data privacy regulations and cyber threats push more people to want visibility into their own devices.
v2rayNG is a free Android app that lets users route their internet traffic through proxy servers, effectively bypassing geographic restrictions and internet censorship. Think of it as a sophisticated VPN alternative that gives users control over how and where their internet connection travels.
Why it matters: With over 51,000 stars on GitHub, this project signals massive demand for privacy and censorship-circumvention tools in markets where internet access is restricted — particularly in Asia — representing a significant user base that competitors and investors in the VPN and privacy space should not ignore. For product teams building privacy or connectivity apps, the scale of adoption here highlights a real gap in mainstream app stores that open-source tools are filling.
PayloadsAllTheThings is a massive, community-built reference library used by security professionals to test websites and applications for vulnerabilities — essentially a cookbook of attack techniques that ethical hackers use to find weaknesses before bad actors do. With over 75,000 people starring it on GitHub, it has become one of the most widely used free resources in the cybersecurity industry for identifying and understanding how web applications can be compromised.
Why it matters: For PMs and founders, this project signals how large and active the 'ethical hacking' and bug bounty market is — companies increasingly pay security researchers to find flaws in their products, and tools like this are the standard playbook those researchers use. If your product is web-facing, understanding that this library exists and is widely used is a reminder that security testing is not optional, and that the techniques to probe your application are freely and broadly available.
Algo VPN is an open-source tool that lets individuals or small teams set up their own private, secure internet connection (VPN) on popular cloud services like Amazon or Google Cloud in minutes, without needing deep technical expertise. Unlike commercial VPN services, you own and control the entire setup, meaning no third-party company has access to your browsing traffic.
Why it matters: With growing concerns around data privacy and remote work security, companies are increasingly looking for alternatives to trusting commercial VPN providers with sensitive employee traffic — Algo offers a self-hosted option that keeps data entirely within an organization's control. Its 30,000+ stars and nearly 190 contributors signal strong market validation for privacy-first infrastructure tools, making it relevant for any product strategy that touches enterprise security or compliance.
This is an Android app that lets users route their internet traffic through Shadowsocks, a widely-used tool for bypassing internet censorship and geo-restrictions — think of it as a privacy tunnel for your phone's connection. It works on Android phones, tablets, Chrome OS devices, and Android TV, giving users a way to access the open internet in regions where content is blocked.
Why it matters: With over 36,000 stars and 11,500 forks on GitHub, this is one of the most popular privacy and censorship-circumvention tools in the world, signaling massive demand in markets like China and Southeast Asia where internet access is heavily restricted. For founders and investors, this represents a proven, large-scale user base hungry for privacy and open-access products — a strong signal for any product strategy targeting underserved users in regulated markets.
JADX is a free tool that lets you look inside Android apps and read their underlying code, even when you don't have the original source files — similar to how you might open a finished product to see how it was made. It comes with both a visual interface and a command-line version, making it accessible to anyone who needs to inspect what an Android app is actually doing under the hood.
Why it matters: For PMs, founders, and investors, this tool is widely used for competitive analysis, security auditing, and verifying what third-party Android apps or SDKs are actually doing with user data — critical concerns in an era of increasing app store scrutiny and privacy regulation. With nearly 50,000 stars on GitHub, its massive adoption signals it has become a standard part of the mobile app security and due diligence toolkit.
This project provides ready-made scripts that let anyone set up their own private, encrypted internet connection (VPN) server in minutes, without needing deep technical expertise. It supports all major devices and operating systems — including iPhone, Android, Windows, and Mac — keeping internet traffic secure, especially on public Wi-Fi networks.
Why it matters: With nearly 27,400 stars and over 6,500 forks, this project signals massive demand for self-hosted privacy tools, reflecting a growing market of businesses and individuals who want data security without relying on third-party VPN services. For founders and investors, this highlights a clear opportunity in the privacy-as-infrastructure space, where companies are willing to invest in owning their own secure networking rather than trusting commercial providers.
Sherlock is a tool that takes a single username and automatically searches for accounts matching that name across more than 400 social media platforms simultaneously, returning a list of everywhere that username exists online. Think of it as a reverse people-search engine — you give it a name like 'johndoe123' and it tells you whether that person has accounts on Instagram, Twitter, Reddit, and hundreds of other sites.
Why it matters: With nearly 73,000 stars on GitHub, this tool reflects massive demand for digital identity investigation, which has direct implications for products in background checking, fraud prevention, hiring, and brand protection. Any startup building in the trust-and-safety, compliance, or online identity verification space should be aware that this capability already exists as a free, widely-used tool — meaning customer expectations for this type of search are already being set.
This project is a practical checklist that helps teams avoid the most common security mistakes when building APIs — the behind-the-scenes connections that let apps and services talk to each other. Think of it as a pre-flight safety checklist, covering everything from how users log in to how sensitive data is protected, translated into 30+ languages for global teams.
Why it matters: Security breaches involving APIs are among the most costly and reputation-damaging incidents a company can face, and this resource gives product and engineering teams a clear, battle-tested standard to build against before launch. With over 23,000 stars on GitHub, it signals strong industry consensus — meaning your competitors and their teams are likely already using it as a benchmark.
This project maintains a continuously updated blocklist that prevents your devices from connecting to websites known for serving ads, malware, and other unwanted content — essentially a community-maintained blacklist for the internet. It works by updating a system-level file (called a 'hosts file') on your computer or network that redirects harmful or unwanted web addresses to nowhere, blocking them before they ever load.
Why it matters: With nearly 30,000 stars on GitHub, this project signals massive consumer demand for privacy and ad-blocking solutions — a market dynamic that every product team building anything ad-supported or data-driven needs to account for. For founders and investors, it also highlights the growing opportunity in privacy-first infrastructure, where open-source community tools are increasingly replacing paid security software.
This is a community-maintained handbook that walks Mac users through step-by-step instructions for locking down their Apple computer against hackers, data breaches, and privacy intrusions. It covers everything from encrypting your hard drive to configuring network settings, aimed at anyone from everyday users to IT professionals who want enterprise-grade protection on their Mac.
Why it matters: With over 22,000 stars on GitHub, this guide signals massive market demand for practical Mac security guidance — a pain point that neither Apple nor most security vendors fully address for individuals and small teams. For founders and PMs building security, privacy, or enterprise Mac-management products, this community's size and engagement is a clear indicator of an underserved audience willing to invest time and effort into protecting their devices.
ImHex is a free, open-source tool that lets security researchers and developers open any file and inspect its raw contents byte-by-byte, revealing the underlying data that most software hides from view. Think of it like a microscope for digital files — it lets experts analyze, decode, and reverse-engineer software, game files, or unknown data formats to understand exactly how they work.
Why it matters: With over 52,000 GitHub stars, ImHex has become a go-to tool in the cybersecurity and reverse-engineering community, signaling strong demand for accessible, powerful file analysis tools among security professionals. For founders and PMs, this highlights a growing market of developers and security teams who need deep visibility into binary data — an audience worth building products and integrations for.
x64dbg is a free, open-source tool for Windows that lets security researchers examine and analyze programs by stepping through them while they run, even without access to the original source code. Think of it like a high-powered microscope for software — it lets experts see exactly what a program is doing under the hood, instruction by instruction.
Why it matters: With cybersecurity threats and malware attacks costing businesses billions annually, tools like x64dbg are essential to the analysts and researchers who investigate breaches, reverse-engineer malicious software, and build better defenses. Its nearly 48,000 GitHub stars signal that it has become a go-to standard in the security research community, meaning products and services built on top of it — or competing with it — are reaching a large, highly skilled professional audience.