# OnixS > OnixS provides commercially supported Direct Market Access (DMA) Software Development Kits (SDKs) for mission-critical electronic trading infrastructure. Products include ultra-low-latency FIX Engines (C++, .NET/C#, Java), venue-specific Market Data Handlers, Order Entry, Trade Capture and Drop Copy SDKs, and FIX Protocol reference tools. Customers include proprietary trading groups, banks, exchanges, energy and commodity trading firms, and ISVs. OnixS is a UK-headquartered specialist software vendor (offices in UK and US). SDKs are licensed on a subscription basis with full commercial support, certified against the relevant venue specifications, and designed to be DORA-ready for regulated financial firms. Full programming guides and API references for every SDK are published at ref.onixs.biz. ## Products - [Products overview](https://www.onixs.biz/products.html): Full catalogue of OnixS SDKs across FIX Engines, directConnect venue handlers, and FIX protocol tools. - [directConnect SDKs](https://www.onixs.biz/directconnect.html): Venue-specific calibrated and certified native protocol and FIX protocol Market Data, Order Routing, Trade Capture and Drop Copy SDKs. - [FIX Engines](https://www.onixs.biz/fix-engine.html): Ultra-low-latency FIX Protocol SDK implementations for FIX-enabling trading and order/execution management systems. - [FIX Protocol Reference & Tools](https://www.onixs.biz/fix-protocol-dictionary-tools.html): Reference materials and developer tooling for FIX, SBE, FIXP and FIXT. ## FIX Engines - [.NET Core / .NET FIX Engine](https://www.onixs.biz/net-fix-engine.html): Cross-platform .NET FIX Engine SDK. - [.NET Framework / C# FIX Engine](https://www.onixs.biz/net-framework-fix-engine.html): C# FIX Engine for .NET Framework. - [C++ FIX Engine](https://www.onixs.biz/cpp-fix-engine.html): High-performance C++ FIX Engine SDK. - [Java FIX Engine](https://www.onixs.biz/java-fix-engine.html): Java FIX Engine SDK. - [FIX FAST Decoder and Encoder](https://www.onixs.biz/fix-fast-decoder-encoder.html): SDK for FAST-encoded FIX message streams. - [FIX <-> FIXML Converter](https://www.onixs.biz/fix-fixml-converter.html): Converts between tag-value FIX and FIXML representations. - [SBE Decoder and Encoder](https://www.onixs.biz/sbe-decoder-encoder.html): Simple Binary Encoding decoder/encoder SDK. ## directConnect venue handlers - [Bloomberg TSOX](https://www.onixs.biz/bloomberg-tsox.html): Bloomberg TSOX FIX connectivity. - [Cboe CFE](https://www.onixs.biz/cboe.html): Cboe Futures Exchange connectivity. - [Cboe EU](https://www.onixs.biz/cboe-europe.html): Cboe Europe connectivity. - [CME Globex](https://www.onixs.biz/cme.html): CME Globex market data, order entry, drop copy and STP. - [CME BrokerTec](https://www.onixs.biz/cme-brokertec.html): CME BrokerTec fixed income connectivity. - [CME EBS](https://www.onixs.biz/cme-ebs.html): CME EBS FX connectivity. - [Deutsche Börse RRH](https://www.onixs.biz/deutsche-borse-regulatory-reporting-hub-fix.html): Deutsche Börse Regulatory Reporting Hub FIX connectivity. - [ICE (Intercontinental Exchange)](https://www.onixs.biz/ice-exchange.html): ICE market data and order entry, including the ICE Binary Order Entry API. - [LME (London Metals Exchange)](https://www.onixs.biz/lme.html): LME connectivity. - [LSE (London Stock Exchange)](https://www.onixs.biz/lse.html): LSE connectivity. - [MTS Markets](https://www.onixs.biz/mts.html): MTS fixed income connectivity. - [Nasdaq NFI](https://www.onixs.biz/nasdaq-nfi.html): Nasdaq Nordic Financial Information connectivity. - [Nodal Exchange](https://www.onixs.biz/nodal-exchange-fix-trade-capture.html): Nodal Exchange FIX trade capture. - [TRADEcho](https://www.onixs.biz/tradecho.html): TRADEcho APA/trade reporting connectivity. - [TT® 7x FIX](https://www.onixs.biz/tt-7x.html): Trading Technologies 7x FIX connectivity. - [TT® Platform](https://www.onixs.biz/tt.html): Trading Technologies platform connectivity. - [Turquoise](https://www.onixs.biz/turquoise-dropcopy.html): Turquoise drop copy. ## Protocol reference - [FIX Protocol overview](https://www.onixs.biz/fix-protocol.html): Introduction to the FIX Protocol and its use with SBE, FIXP and FIXT. - [FIXP overview](https://www.onixs.biz/fixp.html): Reference for the FIX Performance session-layer protocol. - [FIX Dictionary](https://www.onixs.biz/fix-dictionary.html): Online reference dictionary for FIX message types, fields and values across FIX versions. - [FIX Analyser](https://www.onixs.biz/fix-analyser.html): Tool for development and operational support of FIX messaging infrastructure. - [Online FIX Parser](https://www.onixs.biz/fix-parser): Visualises and decodes FIX messages in the browser. - [Direct Market Access explainer](https://www.onixs.biz/insights/direct-market-access): Background article on DMA concepts. ## FIX Protocol specifications - [FIX Dictionary index](https://www.onixs.biz/fix-dictionary.html): Top-level index for the OnixS browseable FIX Protocol dictionary, covering all supported FIX versions and FIXT 1.1. - [FIX 4.0 dictionary](https://www.onixs.biz/fix-dictionary/4.0/index.html): Full message and field reference for FIX 4.0, browseable by MsgType, name, and tag. - [FIX 4.1 dictionary](https://www.onixs.biz/fix-dictionary/4.1/index.html): Full message and field reference for FIX 4.1, browseable by MsgType, name, and tag. - [FIX 4.2 dictionary](https://www.onixs.biz/fix-dictionary/4.2/index.html): Full message and field reference for FIX 4.2, browseable by MsgType, name, and tag. - [FIX 4.3 dictionary](https://www.onixs.biz/fix-dictionary/4.3/index.html): Full message and field reference for FIX 4.3, browseable by MsgType, name, and tag. - [FIX 4.4 dictionary](https://www.onixs.biz/fix-dictionary/4.4/index.html): Full message and field reference for FIX 4.4, browseable by MsgType, name, and tag. - [FIX 5.0 dictionary](https://www.onixs.biz/fix-dictionary/5.0/index.html): Full message and field reference for FIX 5.0, browseable by MsgType, name, and tag. - [FIX 5.0 SP1 dictionary](https://www.onixs.biz/fix-dictionary/5.0.SP1/index.html): Full message and field reference for FIX 5.0 Service Pack 1, browseable by MsgType, name, and tag. - [FIX 5.0 SP2 dictionary](https://www.onixs.biz/fix-dictionary/5.0.SP2/index.html): Full message and field reference for FIX 5.0 Service Pack 2, browseable by MsgType, name, and tag. - [FIX 5.0 SP2 EP299 dictionary (latest)](https://www.onixs.biz/fix-dictionary/latest/messages.html): Latest FIX 5.0 SP2 with Extension Pack 299, the most current FIX Protocol revision indexed by OnixS. - [FIXT 1.1 dictionary](https://www.onixs.biz/fix-dictionary/FIXT1.1/index.html): Full message and field reference for the FIXT 1.1 transport protocol, browseable by MsgType, name, and tag. ## Technical documentation and programming guides - [OnixS Documentation Library](https://ref.onixs.biz/): Index of all OnixS SDK programming guides, API references and technical articles. - [Product versioning](https://ref.onixs.biz/product-versioning.html): Explanation of the OnixS product version numbering scheme. - [.NET FIX Engine Programming Guide](https://ref.onixs.biz/net-core-fix-engine-guide/articles/introduction.html): API reference and usage guide for the .NET Core / .NET FIX Engine. - [.NET Framework FIX Engine Programming Guide](https://ref.onixs.biz/net-fix-engine-guide/): API reference and usage guide for the .NET Framework / C# FIX Engine. - [C++ FIX Engine Programming Guide](https://ref.onixs.biz/cpp-fix-engine-guide/): API reference and usage guide for the C++ FIX Engine. - [Java FIX Engine Programming Guide](https://ref.onixs.biz/java-fix-engine-guide/): API reference and usage guide for the Java FIX Engine. - [.NET SBE Codec Programming Guide](https://ref.onixs.biz/net-sbe-codec-guide/articles/introduction.html): Simple Binary Encoding codec for .NET. - [Java SBE Codec Programming Guide](https://ref.onixs.biz/java-sbe-codec-guide/index.html): Simple Binary Encoding codec for Java. - [C++ B3 Binary UMDF Market Data Handler Guide](https://ref.onixs.biz/cpp-b3-umdf-md-handler-guide/index.html): B3 UMDF binary market data handler in C++. - [C++ B3 BOE Binary Order Entry Handler Guide](https://ref.onixs.biz/cpp-b3-boe-handler-guide/index.html): B3 BOE binary order entry handler in C++. - [C++ BME SENAF Handler Programming Guide](https://ref.onixs.biz/cpp-senaf-handler-guide/): BME SENAF fixed income handler in C++. - [C++ CBOE CFE BOE Handler Guide](https://ref.onixs.biz/cpp-cboe-boe-handler-guide/index.html): CBOE CFE Binary Order Entry handler in C++. - [C++ CBOE CFE Multicast PITCH Market Data Handler Guide](https://ref.onixs.biz/cpp-cboe-pitch-handler-guide/index.html): CBOE CFE PITCH multicast market data handler in C++. - [C++ CME MDP3 Market Data Handler Guide](https://ref.onixs.biz/cpp-cme-mdp3-handler-guide/): CME MDP3 market data handler in C++. - [.NET CME MDP3 Market Data Handler Guide](https://ref.onixs.biz/net-core-cme-mdp3-market-data-handler-guide/): CME MDP3 market data handler in .NET. - [Java CME MDP3 Market Data Handler Guide](https://ref.onixs.biz/java-cme-mdp3-market-data-handler-guide/): CME MDP3 market data handler in Java. - [C++ CME iLink 3 BOE Programming Guide](https://ref.onixs.biz/cpp-cme-ilink3-handler-guide/): CME iLink 3 binary order entry handler in C++. - [Java CME iLink 3 BOE Programming Guide](https://ref.onixs.biz/java-cme-ilink3-handler-guide/): CME iLink 3 binary order entry handler in Java. - [.NET CME iLink 3 BOE Programming Guide](https://ref.onixs.biz/net-core-cme-ilink3-handler-guide/articles/introduction.html): CME iLink 3 binary order entry handler in .NET. - [C++ CME Streamlined Market Data Handler Guide](https://ref.onixs.biz/cpp-cme-streamlined-handler-guide/): CME Streamlined market data feed handler in C++. - [C++ CME MDP Conflated TCP Handler Guide](https://ref.onixs.biz/cpp-cme-conflated-tcp-handler-guide/): CME MDP conflated TCP feed handler in C++. - [C++ CME MDP Conflated UDP Handler Guide](https://ref.onixs.biz/cpp-cme-conflated-udp-handler-guide/): CME MDP conflated UDP feed handler in C++. - [C++ CME Drop Copy Handler Guide](https://ref.onixs.biz/cpp-cme-drop-copy-handler-guide/): CME drop copy handler in C++. - [.NET CME Drop Copy Handler Guide](https://ref.onixs.biz/net-core-cme-dropcopy-handler-guide/): CME drop copy handler in .NET. - [Java CME Drop Copy Handler Guide](https://ref.onixs.biz/java-cme-dropcopy-handler-guide/): CME drop copy handler in Java. - [.NET CME STP Handler Guide](https://ref.onixs.biz/net-core-cme-stp-handler-guide/): CME Straight Through Processing handler in .NET. - [Java CME STP Handler Guide](https://ref.onixs.biz/java-cme-stp-handler-guide/): CME Straight Through Processing handler in Java. - [C++ Euronext Optiq MDG Handler Guide](https://ref.onixs.biz/cpp-euronext-optiq-mdg-handler-guide/): Euronext Optiq Market Data Gateway handler in C++. - [C++ FMX UST BIMP Market Data Handler Guide](https://ref.onixs.biz/cpp-fmx-ust-bimp-handler-guide/): FMX UST BIMP market data handler in C++. - [C++ ICE Binary Order Entry (BOE) Handler Guide](https://ref.onixs.biz/cpp-ice-boe-handler-guide/): ICE Binary Order Entry handler in C++. - [C++ ICE iMpact Multicast Price Feed Handler Guide](https://ref.onixs.biz/cpp-ice-impact-handler-guide/): ICE iMpact multicast market data handler in C++. - [.NET / C# ICE iMpact Multicast Price Feed Handler Guide](https://ref.onixs.biz/net-ice-impact-handler-guide/): ICE iMpact multicast market data handler in .NET. - [Java ICE iMpact Multicast Price Feed Handler Guide](https://ref.onixs.biz/java-ice-impact-handler-guide/): ICE iMpact multicast market data handler in Java. - [ICE iMpact Wireshark Dissector](https://ref.onixs.biz/ice-impact-wireshark-dissector.html): Wireshark dissector for ICE iMpact protocol analysis. - [C++ MTS Cash/SDP Handler Guide](https://ref.onixs.biz/cpp-mts-cash-sdp-handler-guide/): MTS Cash SDP handler in C++. - [C++ MTS BondVision/SDP Handler Guide](https://ref.onixs.biz/cpp-mts-bondvision-sdp-handler-guide/): MTS BondVision SDP handler in C++. - [C++ eSpeed ITCH Multicast Market Data Handler Guide](https://ref.onixs.biz/cpp-espeed-itch-market-data-handler-guide/): Nasdaq eSpeed ITCH multicast market data handler in C++. - [C++ Eurex T7 EDCI Handler Guide](https://ref.onixs.biz/cpp-eurex-edci-handler-guide/): Eurex T7 Enhanced Drop Copy Interface handler in C++. - [C++ Eurex T7 EMDI / EOBI / RDI Handler Guide](https://ref.onixs.biz/cpp-eurex-emdi-handler-guide/): Eurex T7 Enhanced Market Data Interface, Enhanced Order Book Interface and Reference Data Interface multicast feed handler in C++. - [C++ Eurex T7 ETI Trading Handler Guide](https://ref.onixs.biz/cpp-eurex-eti-handler-guide/): Eurex T7 Enhanced Trading Interface handler in C++. - [Java Eurex T7 ETI Trading Handler Guide](https://ref.onixs.biz/java-eurex-eti-handler-guide/): Eurex T7 Enhanced Trading Interface handler in Java. - [C++ Tullett Prebon SURF Handler Guide](https://ref.onixs.biz/cpp-tp-surf-handler-guide/): Tullett Prebon SURF handler in C++. - [Detecting TCP congestion using OnixS FIX Engines and Trading Handlers](https://ref.onixs.biz/detecting-tcp-congestion.html): How to detect and respond to TCP congestion in OnixS-based systems. - [FIX Message reference](https://ref.onixs.biz/fix-message.html): Reference article on FIX message structure. - [FIX Repeating Group reference](https://ref.onixs.biz/fix-repeating-group.html): Reference article on FIX repeating groups. - [FIXML Tutorial](https://ref.onixs.biz/fixml-tutorial.html): Introduction to FIXML. - [Garbage Collection Load Testing using .NET API](https://ref.onixs.biz/garbage-collection-load-testing-dotnet.html): GC load testing techniques for .NET. - [Lost multicast packets troubleshooting](https://ref.onixs.biz/lost-multicast-packets-troubleshooting.html): Diagnosing multicast packet loss in market data feeds. - [Sending One Million FIX messages using .NET](https://ref.onixs.biz/sending-one-million-fix-messages-dotnet.html): Performance benchmark article for the .NET FIX Engine. - [Sending One Million FIX messages using Java](https://ref.onixs.biz/sending-one-million-fix-messages-java.html): Performance benchmark article for the Java FIX Engine. ## Company - [About OnixS](https://www.onixs.biz/about.html): Company background and team. - [Support](https://www.onixs.biz/support.html): Customer technical and sales support information. - [Contact us](https://www.onixs.biz/contact-us): Office locations and contact details (UK +44 20 7117 0111, US +1 312 999 6040, sales@onixs.biz, support@onixs.biz). - [Free 30-day evaluation](https://www.onixs.biz/download-selections.html): Request evaluation SDK downloads tailored to target venue and codebase. ## Insights and release notes - [All insights](https://www.onixs.biz/insights): Articles on FIX, binary protocols, venue API changes, DORA and trading infrastructure. - [All release notes](https://www.onixs.biz/release-notes): Versioned release notes for every OnixS SDK. - [The OnixS DORA-ready advantage](https://www.onixs.biz/insights/onixs-dora-ready-advantage): How commercial support and OnixS SDK design map to DORA requirements. - [FIX vs proprietary binary protocols](https://www.onixs.biz/insights/fix-vs-proprietary-binary-protocols-pros-cons-for-modern-trading): Trade-offs between FIX and proprietary binary protocols. - [B3 Binary APIs adoption path](https://www.onixs.biz/insights/a-practical-adoption-path-for-b3-binary-apis-from-market-data-integration-to-production-trading): Implementation guidance for B3 PUMA binary market data and order entry. - [ICE Binary Order Entry API as a structural shift](https://www.onixs.biz/insights/why-the-ice-binary-order-entry-api-is-a-structural-shift-not-just-a-faster-interface): Why the ICE Binary OE API is more than a performance upgrade. - [CME market data with OnixS and Databento](https://www.onixs.biz/insights/accessing-cme-market-data-with-onixs-and-databento): Combining OnixS handlers with Databento for CME access. ## Optional - [Privacy, cookies and data policy](https://www.onixs.biz/cookies-and-privacy.html) - [Sitemap](https://www.onixs.biz/sitemap.html)