# Callback Technologies

> Callback Technologies is a software company specializing in filesystem virtualization, security monitoring, and kernel-level development. The company delivers kernel drivers, component libraries, and virtual drive applications trusted by organizations including Adobe, Amazon, Citrix, Intel, HP, Lenovo, and Trend Micro. Privately held with 20+ years of kernel development expertise.

- Website: https://www.callback.com/
- Products: https://www.callback.com/products/
- Knowledge Base: https://www.callback.com/kb/
- Documentation Hub: https://www.callback.com/docs/
- Support: https://www.callback.com/support/
- Downloads: https://www.callback.com/downloads/
- Subscriptions: https://www.callback.com/subscriptions/

## Company Overview

Callback Technologies provides native software components for kernel-level filesystem and network operations across .NET, Java, C++, Python, Rust, Go, Delphi, Qt, macOS, Swift, iOS, Android, and Linux. Products fall into three categories: Kernel Drivers (developer SDKs for filesystem and network interception), Component Libraries (developer SDKs for sync, storage, shell integration, and cloud storage mounting), and Virtual Drives (end-user utilities for mounting remote storage as local drives).

Support options include free access to the knowledge base and support tickets for evaluators, standard technical support included with purchase, and premium priority support with guaranteed next-business-day response available as a paid add-on. Custom development services are available via sales@callback.com.

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## Product Catalog

The following sections list every product available from Callback Technologies, organized by category. Each entry includes a description, key capabilities, and links to documentation.

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### Kernel Drivers

#### CBFS Connect
An SDK for creating and managing virtual filesystems from any data source — local or remote files, cloud storage, databases, or dynamically-generated content. Filesystem operations are proxied into callback events, eliminating the need to write kernel-level driver code. Supports named streams, directory change notifications, reparse points, hard links, quotas, custom disk icons, NTFS security with granular access control, transparent encryption, Docker container support, a local NFS 4.1 server component, and cross-platform FUSE integration. Licensing starts at $2,499/year per developer (CBFS Developer Subscription, all editions); distribution licenses start at $4,999/year (up to 100 deployment machines). OEM licensing available on request.

- Product Page: https://www.callback.com/cbfsconnect/
- Online Documentation: https://www.callback.com/docs/?pid=CC
- Pricing / Order: https://www.callback.com/cbfsconnect/order
- Download Trial: https://www.callback.com/cbfsconnect/download

#### CBFS Filter
A filter driver library for intercepting and controlling filesystem, registry, and process manager operations without writing driver code. Features rules-based filtering, on-the-fly file encryption with custom algorithms, file isolation (different processes see different file contents), virtual file and registry key creation, process and thread activity monitoring, and comprehensive system activity logging. More reliable than FileSystemWatcher. Single CAB file deployment.

- Product Page: https://www.callback.com/cbfsfilter/
- Online Documentation: https://www.callback.com/docs/?pid=CF
- Pricing / Order: https://www.callback.com/cbfsfilter/order
- Download Trial: https://www.callback.com/cbfsfilter/download

#### CBFS Encrypt
A filter driver library for transparent, on-the-fly file encryption and decryption with process-based access control. Encrypts files on disk and decrypts them only for authorized processes. Different processes viewing the same file see different content based on permissions. Uses a rules-based engine for targeting specific file requests. Single CAB file deployment. Windows only.

- Product Page: https://www.callback.com/cbfsencrypt/
- Online Documentation: https://www.callback.com/docs/?pid=CE
- Getting Started: https://www.callback.com/kb/articles/cbfsencrypt-getting-started-with-cbencrypt
- Pricing / Order: https://www.callback.com/cbfsencrypt/order
- Download Trial: https://www.callback.com/cbfsencrypt/download

#### PCAP Filter
A cross-platform driver and component library for real-time network packet capturing, filtering, and modification. Supports real-time packet interception and modification, industry-standard filter syntax compatible with Wireshark and tcpdump, custom security policy implementation for blocking or rerouting packets, flexible capture modes for detailed inspection or statistical analysis, and network activity auditing. Built on the proven libpcap/BPF expression engine.

- Product Page: https://www.callback.com/pcapfilter/
- Online Documentation: https://www.callback.com/docs/?pid=CP
- Pricing / Order: https://www.callback.com/pcapfilter/order
- Download Trial: https://www.callback.com/pcapfilter/download

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### Component Libraries

#### CBFS Cloud
A development library for building applications that mount remote and cloud-based storage as local virtual drives in code, without requiring end-user setup or configuration. Connects to SFTP servers, Amazon S3 and S3-compatible storage, WebDAV servers, Microsoft OneDrive, Google Drive, Azure Blob Storage, Azure Files, SharePoint, and NFS servers through a single unified API. Features built-in intelligent caching to minimize latency and reduce redundant network calls, programmatic drive lifecycle management, and transparent access to remote files through standard file system APIs. Applications and users interact with remote data as if it were local, with no changes to existing workflows required.

- Product Page: https://www.callback.com/cbfscloud/
- Online Documentation: https://www.callback.com/docs/?pid=CL
- Getting Started: https://www.callback.com/kb/articles/cbfscloud-quickstart
- Download Trial: https://www.callback.com/cbfscloud/download

#### CBFS Sync
A cross-platform library for seamless bi-directional synchronization between local filesystems and cloud storage or other remote repositories. Uses OS-native infrastructure (Cloud Filter API on Windows, FileProvider on macOS, FUSE on Linux) similar to how Microsoft OneDrive operates. Features local folder monitoring, asynchronous non-blocking operation, and a unified API across Windows (Intel/ARM), Linux, and macOS. Mobile support in development.

- Product Page: https://www.callback.com/cbfssync/
- Online Documentation: https://www.callback.com/docs/?pid=CY
- Pricing / Order: https://www.callback.com/cbfssync/order
- Download Trial: https://www.callback.com/cbfssync/download

#### CBFS Vault
A library for packaging multiple files into a single vault — a "filesystem within a file" — with compression, encryption, and random access. Supports per-file and whole-filesystem encryption using modern cryptographic algorithms, journaling for filesystem integrity during unexpected interruptions, alternate data streams, custom metadata, and deployment in hard drives, flash cards, database records, or raw memory. Reduces filesystem calls through user-mode operation. Available for .NET, C++, Java, Python, Rust, Go, Android, Delphi, Qt, macOS, and iOS.

- Product Page: https://www.callback.com/cbfsvault/
- Online Documentation: https://www.callback.com/docs/?pid=CT
- Pricing / Order: https://www.callback.com/cbfsvault/order
- Download Trial: https://www.callback.com/cbfsvault/download

#### CBFS Shell
A library for extending and customizing Windows File Explorer with virtual folders, custom context menus, toolbars, detail columns, and overlay icons. Operates out-of-process via RPC, keeping File Explorer stable even if the shell application encounters errors. Supports drag, drop, copy, paste, cut, delete operations; thumbnails; ribbons; and property pages. Available for .NET, C++, Python, Rust, Go, Delphi, and Qt.

- Product Page: https://www.callback.com/cbfsshell/
- Online Documentation: https://www.callback.com/docs/?pid=CX
- Pricing / Order: https://www.callback.com/cbfsshell/order
- ShellFolder Getting Started: https://www.callback.com/kb/articles/cbfsshell-Getting-Started-With-ShellFolder
- ShellMenu Getting Started: https://www.callback.com/kb/articles/cbfsshell-Getting-Started-With-ShellMenu
- ShellOverlays Getting Started: https://www.callback.com/kb/articles/cbfsshell-Getting-Started-With-ShellOverlays
- Download Trial: https://www.callback.com/cbfsshell/download

#### CBFS Disk
A library for creating and managing virtual disk drives backed by standalone datastores. Virtual disk contents are exposed as a single data block storable in memory, local storage, or remote locations. Supports FAT, NTFS, and other filesystem formats; virtual snapshots for rollback; whole-disk encryption; network mounting points; session-local mounting; PnP device emulation; and UNC path support. Single CAB file deployment. Available for .NET, C++, Java, Python, Rust, Go, Delphi, and Qt.

- Product Page: https://www.callback.com/cbfsdisk/
- Online Documentation: https://www.callback.com/docs/?pid=CD
- Pricing / Order: https://www.callback.com/cbfsdisk/order
- Download Trial: https://www.callback.com/cbfsdisk/download

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### Virtual Drives

Virtual Drives are end-user utilities that mount remote or encrypted storage as local drives, enabling file access through Windows Explorer, Linux file managers, or the command line without manual upload/download.

#### SFTP Drive
Mounts SFTP servers as local drives on Windows and Linux. Supports password, key-based, and combined authentication; Authentication Agent, file-based, and Security Token/Smart Card key types; multiple saved connection profiles; PuTTY/FileZilla settings import; FIPS 140-2 mode; and Windows ARM64. Files are accessible through Windows Explorer or the command line. Perpetual licenses: $99 (Desktop, single user) or $499 (Server, unlimited users); includes one year of upgrades. Optional renewal available. Site and OEM licenses available on request.

- Product Page: https://www.callback.com/sftpdrive/
- Online Documentation: https://cdn.callback.com/help/NDJ/app
- Pricing / Order: https://www.callback.com/sftpdrive/order
- Windows Quick Start: https://www.callback.com/kb/articles/sftpdrive-quickstart
- Linux Quick Start: https://www.callback.com/kb/articles/sftpdrive-linux-quickstart
- Download Trial: https://www.callback.com/sftpdrive/download

#### AES Drive
Mounts a virtual encrypted drive using XTS-AES 256. Files are transparently encrypted on disk and decrypted on access. Supports quick mount/dismount, automatic session timeout, portable format with no vendor lock-in, and compatibility with other AES-compliant tools. Works with standard file managers. Perpetual licenses: $99 (Desktop, single user) or $499 (Server, unlimited users); includes one year of upgrades. Site and OEM licenses available on request.

- Product Page: https://www.callback.com/aesdrive/
- Online Documentation: https://cdn.callback.com/help/NEJ/app
- Pricing / Order: https://www.callback.com/aesdrive/order
- Getting Started: https://www.callback.com/kb/articles/aesdrive-quickstart
- Download Trial: https://www.callback.com/aesdrive/download

#### DAV Drive
Mounts WebDAV servers as local virtual drives on Windows, Linux, and macOS (including Windows ARM64). Supports multiple saved connection profiles, standard file operations (move, copy, rename, delete), and can run as a Windows service or desktop application. GUI and command-line configuration. Currently in beta; pricing not yet listed.

- Product Page: https://www.callback.com/davdrive/
- Online Documentation: https://cdn.callback.com/help/NWJ/app
- Order: https://www.callback.com/davdrive/order
- Download Trial: https://www.callback.com/davdrive/download

#### S3 Drive
Mounts S3-compatible object storage as a local virtual drive on Windows and Linux (including Windows ARM64). Supports Amazon S3, DigitalOcean Spaces, Wasabi, Backblaze B2, IBM Cloud Object Storage, Akamai/Linode, Oracle Cloud Storage, Cloudflare R2, IDrive e2, MinIO, Scality, Seagate Lyve Cloud, Oort DSS, and custom providers. Features multiple connection profiles, a flexible local cache for random read-write access, FIPS 140-2 mode, and can run as a Windows service. Perpetual licenses: $99 (Desktop, single user) or $499 (Server, unlimited users); includes one year of upgrades. Site and OEM licenses available on request.

- Product Page: https://www.callback.com/s3drive/
- Online Documentation: https://cdn.callback.com/help/NBJ/app
- Pricing / Order: https://www.callback.com/s3drive/order
- Windows Quick Start: https://www.callback.com/kb/articles/s3drive-quickstart
- Linux Quick Start: https://www.callback.com/kb/articles/s3drive-linux-quickstart
- Download Trial: https://www.callback.com/s3drive/download

#### NFS Drive
Mounts NFS servers as local virtual drives using NFS 4.0 protocol. Supports multiple saved connection profiles, standard file operations via GUI and command line, and can run as a Windows service or desktop application. Compatible with Windows ARM64. Currently in beta; pricing not yet listed.

- Product Page: https://www.callback.com/nfsdrive/
- Online Documentation: https://cdn.callback.com/help/NNJ/app
- Order: https://www.callback.com/nfsdrive/order
- Download Trial: https://www.callback.com/nfsdrive/download

#### Azure Drive
Mounts Azure File Storage as a local virtual drive. Supports multiple saved connection profiles, all standard directory and file operations (move, copy, rename) via GUI and command line, and can run as a Windows service or desktop application. Windows ARM64 supported. Perpetual licenses: $99 (Desktop, single user) or $499 (Server, unlimited users); includes one year of upgrades. Site and OEM licenses available on request.

- Product Page: https://www.callback.com/azuredrive/
- Online Documentation: https://cdn.callback.com/help/NAJ/app
- Pricing / Order: https://www.callback.com/azuredrive/order
- Quick Start: https://www.callback.com/kb/articles/azuredrive-quickstart
- Download Trial: https://www.callback.com/azuredrive/download

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## Supported Platforms

Kernel Drivers and Component Libraries are available as native components for the following development platforms:

- .NET (Framework 4.0+, .NET 5–10 — Windows)
- Java (JDK 1.7+ — Windows, Linux, macOS)
- C++ (Windows, Linux, macOS)
- Delphi (versions 6 through RAD Studio 13)
- Go (1.13+)
- Rust
- Python 3
- Qt (4.8 and 5)
- macOS (XCFramework — Swift 5+, Objective-C)
- iOS (XCFramework)
- Android
- Linux (standalone)

Virtual Drives support Windows, Linux, and macOS as end-user applications.

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## Support & Documentation

- Knowledge Base (searchable articles, guides, tutorials): https://www.callback.com/kb/
- All product documentation (choose product and platform): https://www.callback.com/docs/
- Submit a support ticket: https://www.callback.com/support/submit
- Support overview: https://www.callback.com/support/
- Submit a feature request: https://www.callback.com/forms/request/
- Custom development inquiries: sales@callback.com

Support tiers:
- **Basic** (free for evaluators): Knowledge base access and support tickets for the latest product version.
- **Standard** (included with purchase): Technical questions and code fixes covering the latest and previous versions.
- **Premium** (paid add-on): Priority phone and email support with guaranteed next-business-day response, sample application creation, and source code analysis.

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## CBFS Developer Subscription

The CBFS Developer Subscription is a single package providing access to all developer libraries across all supported platforms, eliminating the need to purchase individual products. Priced at $2,499/year per developer (single developer, all editions, all platforms). Includes premium support and immediate access to all upgrades during the subscription period.

Included products:
- CBFS Connect
- CBFS Cloud
- CBFS Filter
- CBFS Encrypt
- CBFS Sync
- CBFS Shell
- CBFS Vault
- PCAP Filter

Benefits include:
- All products and all platform editions in a single license
- Per-developer licensing (use from any location)
- Free upgrades to all releases during the subscription period
- Cost significantly lower than purchasing products individually

- Subscriptions Page: https://www.callback.com/subscriptions/
- Order / Pricing: https://www.callback.com/subscriptions/order