Difference between VelocityDB and XAP

1. VelocityDB :
It is .NET Object Database that can be embedded/distributed and extended to a graph data model (VelocityGraph) Database is fast and low memory consuming. It is an extremely high performance, easy to use, scalable, embeddable, and distributable object database system.

2. XAP :
It is high-performance in-memory data grid for mission-critical applications and provides an essential set of data store features, such as transactions, indexes, and query language (SQL-like queries). It is a file format used to install and distribute application software.

Difference between VelocityDB and XAP :

VelocityDB	XAP
It is developed by VelocityDB Inc and initially released on 2011.	It is developed by Gigaspaces Technologies and initially released on 2000.
Its server operating systems of VelocityDB is Any that supports .NET	Its server operating systems of XAP Linux, macOS, Solaris, Windows.
Its primary database model is Graph DBMS and Object oriented DBMS	Its primary database model is Document store and Key-value store.
Absence of Secondary database models in VelocityDB	Secondary database models of XAP is Object oriented DBMS.
It supports .Net programming languages.	It supports .Net, C++, Java programming languages.
APIs and other access methods of VelocityDB is .Net	It supports GigaSpaces LRMI, Hibernate, JCache, JDBC, JPA, ODBC, RESTful HTTP API, Spring Data.
It has Data Schema.	Data Schema of XAP is schema-free.
It has Implementation language-C# .	Implementation language of XAP is Java, C++, .Net.
It has transaction concepts is ACID (atomicity, Consistency, Isolation, and Durability).	XAP has ACID (atomicity, Consistency, Isolation, and Durability) concepts transaction concepts.
Absence of Replication methods	Replication methods of XAP- Master-master replication and Master-slave replication.
It has Immediate Consistency concept.	It has Immediate Consistency concept.
Sharding is a Partitioning methods of VelocityDB.	Sharding is a Partitioning methods of XAP.