Zeal
DevDocs
Dash for macOS
Velocity
DASH
Papaya Global
Greenboard
Zest
ForthWrite
Superhuman
Gemini
Lavender
Mailmeteor
Spark Mail
Zeal is a free and open-source offline documentation browser for developers. You download docsets for the languages, frameworks, and libraries you use, and Zeal lets you search across all of them at once and jump straight to the symbol, class, or function you need. Because everything is stored locally, lookups are instant and work with no internet connection, which makes Zeal useful on flights, on locked-down networks, or any time you want to stay focused without a browser full of tabs.
Zeal is a native desktop application rather than a web wrapper, so it launches quickly and stays light on resources. It requires no account and includes no built-in tracking, and it runs on both Linux and Windows. Docsets cover hundreds of technologies and can be added or updated from within the app.
ForthWrite is an AI email writing assistant for Gmail and Outlook that learns your writing style from your real sent mail. The more you use it, the more it sounds like you. Get smart drafts in seconds, auto-draft replies before you open your inbox, and maintain your personal voice at scale. Free to start, no credit card required. Works inside Gmail and Outlook on the web.
How it works
ForthWrite captures your tone, sentence rhythm, and sign-offs from your actual sent emails, then uses that profile to generate drafts that match how you write, not a generic AI voice. Every draft you edit or send improves the model over time.
Key features
Who uses it
Professionals who send high volumes of relationship-critical email: lawyers, financial advisors, recruiters, account executives, founders, and anyone who wants their inbox handled without sounding like a chatbot wrote it.
Pricing
Free tier includes 10 drafts per week with no credit card required. Paid plans start at $12/month and include unlimited drafts, custom persona prompts, and auto-draft.
Zeal ForthWriteZeal's answer
Zeal's answer
C++ and Qt 6, with Qt WebEngine (Chromium) rendering the documentation pages. SQLite powers the search index, libarchive handles docset extraction, and the build uses CMake and Ninja.
ForthWrite's answer:
Next.js, React, Supabase, Anthropic Claude, OpenAI, Stripe, Vercel, Chrome Extensions API
Zeal's answer
Zeal started in 2013 as a free, open-source way to get Dash-style offline documentation on Linux, where Dash (macOS-only) was not available. It adopted the same docset format, grew Windows support, and has been developed in the open ever since, maintained by a small team in their spare time with contributions from the community.
ForthWrite's answer:
Built out of frustration with AI writing tools that produce text that sounds nothing like the person sending it, and as a way to handle large amounts of daily email. The core insight was that your sent mail is the best training data you already have, and no tool was using it.
Zeal's answer
Software developers who look up reference documentation many times a day: languages, frameworks, libraries, and tools. More broadly, anyone who wants a personal reference library that works without internet access. The docset catalog is developer-focused today and gradually broadening.
ForthWrite's answer:
Professionals who send high volumes of relationship-critical email and cannot afford to sound generic: lawyers, financial advisors, recruiters, account executives, consultants, and founders managing their own inbox.
Zeal's answer
Compared to Dash, Zeal is free, open-source, and runs on Linux and Windows rather than macOS.
Compared to web-based tools like DevDocs, Zeal is a native desktop application that works with no connection at all, supports a much larger docset catalog, and can be summoned from anywhere with a global shortcut. Compared to searching the web, lookups are instant, ad-free, and exactly scoped to the libraries you actually use.
ForthWrite's answer:
Most AI email tools give you a blank box and a "write for me" button. ForthWrite builds a voice profile from your sent history and gets more accurate with every draft you edit or send. Unlike ChatGPT or Gemini, it works natively inside Gmail and Outlook with no copy-paste. Unlike Lavender, it writes the draft, not just scores it.
Zeal's answer
Zeal combines things that usually come as trade-offs: it is fully offline, native, and free.
All documentation is stored locally and searched with instant fuzzy matching across every docset you have installed at once. It uses the same docset format as Dash, so the catalog covers every major language, framework, and tool, while running on Linux and Windows as open-source software under GPL-3.0-or-later.
ForthWrite's answer:
ForthWrite learns your writing style from your actual sent mail, not a generic prompt. Every draft sounds like you wrote it because it was trained on how you actually write. It also auto-drafts replies before you open your inbox, so your email is partially handled before your day starts.
I built ForthWrite because I kept sending emails that sounded like they came from the same generic AI as everyone else. After launching it, I still use it for my own inbox every day, which is about the most honest endorsement I can give.
The Chrome extension lives inside Gmail and Outlook on the web. Open a thread, hit Alt+Shift+D, and a draft comes back in your voice, not a template. The free tier is real: 10 drafts per week, no API key, no credit card. Voice matching is included on free, because that is the point.
What keeps it useful compared to Gemini or a chat tab: it learns from what you actually send. Every edit you make before hitting send becomes a signal. Over time the drafts drift closer to how you really write, and the dashboard shows the improvement curve so you can see it happening.
The web compose surface lets you draft from forthwrite.ai without installing anything, useful for people who want to try before committing to the extension.
Standard adds recipient-aware and intent-aware drafting plus AI coaching. Pro adds auto-draft (replies waiting when you open Gmail), batch replies, and Prompt Lab for version-controlling your prompts. Teams adds a shared persona and seat-level analytics.
ForthWrite is not for everyone. If you just need quick replies and tone does not matter, Gemini is free and already in your inbox. ForthWrite is for people where tone does matter: client communication, relationship-driven threads, external correspondence where sounding off costs something real.
Disclosure: I am the founder and use it daily. Happy to answer questions in the comments.
Based on our record, Zeal seems to be more popular. It has been mentiond 67 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
This isn't a new idea for developer tools. DevDocs, Zeal, and Dash have offered offline documentation browsing for years. What's new is applying this architecture to AI agents โ giving your coding assistant the same offline, instant, version-accurate access to docs that you'd want for yourself. - Source: dev.to / 5 months ago
Zeal might be what you are looking for - https://zealdocs.org/. - Source: Hacker News / 8 months ago
I find that self hosting "devdocs" [1] and having zeal (on linux) [2] solve a lot of these problems with the offline docs. [1] https://github.com/freeCodeCamp/devdocs. - Source: Hacker News / about 1 year ago
Yeah, I keep thinking that CHM was the peak format for offline docs. Today we have Kiwix [0] and Dash/Zeal [1] โ both amazing projects, but somehow they feel more complex, and the formats they use arenโt as ubiquitous. [0]: https://kiwix.org/en/ [1]: https://kapeli.com/dash for macOS, https://zealdocs.org/ for others. - Source: Hacker News / over 1 year ago
There's also Zeal (https://zealdocs.org/) which is basically the same as Dash but open source and runs on non-Mac devices. - Source: Hacker News / over 2 years ago
DevDocs - Open source API documentation browser with instant fuzzy search, offline mode, keyboard shortcuts, and more
Superhuman - Superhuman is an email management tool.
Dash for macOS - Dash is an API Documentation Browser and Code Snippet Manager. Dash searches offline documentation of 200+ APIs and stores snippets of code. You can also generate your own documentation sets.
Gemini - Gemini, formerly known as Bard, is a generative artificial intelligence chatbot developed by Google. Based on the large language model (LLM) of the same name, it was launched in 2023 in response to the rise of OpenAI's ChatGPT.
Velocity - Velocity gives your Windows desktop offline access to over 150 API documentation sets provided by...
Lavender - Realtime coaching for sales emails.
