# Basics
The following provides you with basic information about the ELO environment.
# Difference between ELOprofessional and ELOenterprise
- In terms of operating systems, ELOprofessional only supports Microsoft Windows. By contrast, ELOenterprise is platform-independent.
- Unlike ELOenterprise, ELOprofessional is not multi-tenant capable.
- ELOprofessional systems are only cluster-ready to a certain extent. They only allow for hot standby operation of individual components. ELOenterprise systems, however, are fully cluster-ready.
- With ELOprofessional, server processes may only be distributed within the same host, i.e. on a server system. By contrast, with ELOenterprise processes can be distributed across multiple hosts (VMs or physical servers).
- With ELOprofessional, the ELO server components (e.g. ELOas) can be distributed across multiple Tomcat servers as long as they are located on one server system (VM or physical server). In contrast, with ELOenterprise, Tomcat servers can be installed on multiple server systems (VMs or physical servers).
Area |  ELOenterprise |  ELOprofessional |
|---|---|---|
| Operating system | Platform-independent | Windows |
| Architecture | SOA-compliant modular client/server architecture | SOA-compliant modular client/server architecture |
| Maximum number of repositories | Unlimited | 20 per repository server |
| Maximum number of users | Unlimited | 1000 |
| Maximum number of documents | 2 billion per repository | 100 million |
| Maximum levels per repository | 254 | 254 |
| Database | PostgreSQL/Microsoft SQL/Oracle/IBM DB2 | PostgreSQL/Microsoft SQL/Oracle/IBM DB2 |
| Multi-tenant capable | ✔ | - |
| Portal integration | ✔ | ✔ |
| Status log for central monitoring systems | ✔ | ✔ |
| Distributable server processes | ✔ | Single host |
| Cluster capacity | ✔ | Hot standby |
# Java support
Please note
ELOprofessional and ELOenterprise should always be installed on a 64-bit operating system.
Overview of Java support on different operating systems
| Windows | macOS | Linux |
|---|---|---|
| 64-bit installation | Yes | Yes |
| 32-bit installation (or AFM) | Installation allowed | Installation not allowed |
| Running the client | Only 64-bit | Only 64-bit |
# Database support
| ELO product | Microsoft SQL Server 2017 | Microsoft SQL Server 2019 | Microsoft SQL Server 2022 | Oracle 19c | Oracle 21c | IBM DB2 11.5 | PostgreSQL 13.xx and higher |
|---|---|---|---|---|---|---|---|
| ELOprofessional Server Windows | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
| ELOenterprise Server Windows | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
| ELOenterprise Server Linux | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
| ELO BLP* | - | - | - | - | - | - | - |
| ELO DocXtractor II 5.x** | ✔ | ✔ | ✔ | ✔ | - | - |
* MS Express is also supported if only Oracle is available.
** Refer to the document ELO DocXtractor II 5.x hardware and software requirements in the ELO SupportWeb for a detailed list of supported database driver versions. Please note this file is only available in German.
Please note
Microsoft SQL Server 2016 is no longer supported. This is because of security issues due to insecure encryption functions.