Yes, eMark creates Adobe Reader DC compatible PDF signatures that can be verified in Adobe Reader DC and Adobe Acrobat. Signatures created with eMark follow PDF signature standards (ISO 32000, PAdES) and are fully compatible with Adobe products. When you sign a PDF with eMark, it can be opened and verified in Adobe Reader DC, Adobe Acrobat DC, and all other major PDF viewers without any issues.

eMark is a free, open-source Adobe Reader DC alternative for PDF signing and digital signatures. It's a professional PDF signing software that works on Windows, Linux, and macOS. eMark supports USB tokens (eToken, SafeNet, Gemalto), HSM devices (PKCS#11), smart cards, PKCS#12/PFX certificates, and Windows Certificate Store for professional PDF signing. It provides an Adobe Reader-like interface with signature field detection, customizable signature appearance, and comprehensive signature verification capabilities.

Yes, eMark provides comprehensive support for USB tokens (eToken, SafeNet, Gemalto), Hardware Security Modules (HSM) via PKCS#11, smart cards, PKCS#12/PFX certificates, and Windows Certificate Store. It's a true multi-certificate, multi-platform PDF signing solution. You can use your existing hardware security tokens and certificates without any additional configuration in most cases.

Yes, eMark is completely free and open-source software licensed under AGPL-3.0. You can download, use, and modify it without any cost, registration, or subscription. There are no hidden fees, no trial periods, and no limitations on features. It's free forever for personal and commercial use.

eMark supports Windows (7, 10, 11), Linux (Ubuntu, Debian, Fedora, and other distributions), and macOS. It provides consistent cross-platform functionality with the same features and UI across all operating systems. We offer native installers (.exe for Windows, .deb for Linux) and a universal .jar file for all platforms.

Yes, eMark can verify PDF signatures created by Adobe Reader DC, Adobe Acrobat, and other PDF signing tools. It provides detailed certificate validation, trust chain verification, and signature integrity checks compatible with Adobe standards. You'll see comprehensive information about the signature, certificate validity, trust status, and document integrity.

eMark requires Java SE 8 (JDK or JRE) to run. It is specifically designed for Java 8 and is not compatible with Java 7 or Java 9+. You'll also need a digital certificate (USB token, HSM, PKCS#12/PFX, or Windows Certificate Store), minimum 2 GB RAM (4 GB recommended), and about 100 MB of disk space. Windows 7/10/11, Linux (any distribution), or macOS are supported.

Yes, eMark supports RFC 3161 timestamping (TSA - Time Stamp Authority) for adding trusted timestamps to your PDF signatures. This ensures long-term validation (LTV) of your signatures even after the signing certificate expires. You can configure your preferred TSA server in the settings.

Absolutely. eMark is completely offline and privacy-focused - it never uploads your PDFs or certificates to any cloud service. All processing happens locally on your computer. Your private keys never leave your hardware security device (USB token, HSM, smart card). eMark is open-source, so you can review the code yourself to verify its security and privacy practices.

Yes, eMark is licensed under AGPL-3.0, which allows you to use it freely for both personal and commercial purposes. You can use it in your business for signing contracts, invoices, legal documents, and any other business documents without any licensing fees or restrictions. If you modify and distribute eMark, you must share your modifications under the same license.

For support, bug reports, or feature requests, please visit our GitHub Issues page. You can also check the documentation and wiki for guides and troubleshooting tips. The community is active and responsive to help with any questions or issues you might encounter.

eMark is a free, open-source alternative focused specifically on PDF signing and verification, while Adobe Acrobat is a paid commercial product with many additional features for PDF editing and creation. eMark excels at digital signature operations with superior support for hardware security devices (USB tokens, HSM, smart cards) and is completely free. If you only need to sign and verify PDFs professionally, eMark provides all the features you need without the cost and complexity of Adobe Acrobat.