1. VelocityDB：
它是.NET对象数据库，可以嵌入/分发并扩展为图形数据模型(VelocityGraph)。数据库速度快，内存消耗低。 VelocityDB是一个极高性能，易于使用，可伸缩，可嵌入和可分发的对象数据库系统。
2. Virtuoso：
它是支持对表示为关系表和/或属性图的数据进行管理的中间件。它是一个多模型混合型RDBMS，它拥有主要数据库模型，如Graph DBMS，Native XML DBMS，Relational DBMS，RDF存储，搜索引擎。它旨在利用操作系统线程支持和多个CPU的优势。 Virtuoso对象关系数据库(ORDBMS)支持实体完整性和引用完整性。
VelocityDB和Virtuoso之间的区别：
| VelocityDB | Virtuoso |
|---|---|
| It is developed by VelocityDB Inc and initially released on 2011 . | It is developed by Virtuoso and initially released on 1998. |
| Its server operating systems of VelocityDB is Any that supports .NET | Its server operating systems of AIX, FreeBSD, HP-UX, Linux, OS X, Solaris, Windows. |
| Its primary database model is Graph DBMS and Object oriented DBMS | Its primary database model is Graph DBMS, Native XML DBMS, Relational DBMS, RDF store, Search engine. |
| Absence of Secondary database models in VelocityDB | Secondary database models of YugabyteDB is Document store. |
| It supports .Net programming languages. | It supports .Net, C, C#, C++, Java, JavaScript, Perl, PHP, Python, Ruby, Visual Basic programming languages. |
| APIs and other access methods of VelocityDB is .Net | Virtuoso supports ADO.NET, GeoSPARQL, HTTP API, JDBC, Jena, RDF API, ODBC, OLE DB, RDF4J API, RESTful HTTP API, Sesame REST HTTP Protocol, SOAP, webservices, WebDAV, XPath, XQuery, XSLT. |
| It has Implementation language-C# . | Implementation language of Virtuoso is C. |
| Its transaction concepts is ACID (atomicity, Consistency, Isolation, and Durability). | It has transaction concept- ACID (atomicity, Consistency, Isolation, and Durability). |
| Absence of Replication methods. | Replication methods of Virtuoso is based on Chain, star, and bi-directional replication, Master-master replication, Master-slave replication. |
| It has Immediate Consistency concept. | It has Consistency concept. |
| Partitioning methods of VelocityDB is Sharding. | There is no partitioning methods. |
| It has not concept of Foreign keys | It has concept of Foreign keys |