An openDCIM and RackTables alternative for small rooms

At a glance

	openDCIM (public pages)	RackTables (public pages)	DC Sim
What it is	Free web-based DCIM for inventory and capacity	Free data center and server room asset management	Browser-based data center simulator and 3D twin
Built for	Replacing spreadsheets for data center inventory, “no matter how small or large”	System and network administrators documenting racks, devices, links and network resources	Small and mid-size data centers and the partners who serve them
Licence and price	GPL v3; free	GPL v2; free	Monitor $5 per rack per month ($49 minimum); Design $490–3,900 one-time per project
How you run it	Self-hosted LAMP server: Apache with SSL, MySQL 5 or later, PHP 8.0 or later, Linux	Self-hosted PHP application with a MySQL database	In the browser; Excel template today, walkthrough on your own file
Status on 27 October 2026	Maintainer seeking a successor; final release 26.01 announced; newest download 23.04 (October 2023)	Latest stable 0.22.0 (February 2022); repository commits in June 2026	Commercial product with a public changelog
Racks and devices	Cabinets, device templates, chassis, multiple rooms	Racks, enclosures, devices mounted in racks	From your sheet, NetBox or Zabbix: rack, U and model per device
Rack and room view	Clickable floor map; graphical cabinet viewer (you supply the images)	Rack diagrams	3D twin with Floor, Air, Water, Fire, Power, Cabling, Network, Device and Token layers
Power	Device → power strip → panel → source feed; integrates with intelligent power strips and UPSs; automatic transfer switches	Not on the public pages	Power chain with A and B feeds, per-phase load and UPS runtime; reads Zabbix directly
Failure what-if	Impact simulation of a panel or source feed outage	Not on the public pages	Fail any UPS, feed, breaker, switch, cooling unit or manifold; dark, one-feed and overloaded lists
Cooling	Space, power and cooling capacity; temperature overlay on the floor map	Not on the public pages	Estimated minutes to 27, 32 and 35 °C at the rack inlets after a cooling failure (zonal model, not CFD)
Network and cabling	Connections inside cabinets and to switches; patch panel path to the endpoint	Physical ports and links; IP addresses and networks, NAT rules, load-balancer configuration	Cabling layer with trace; network topology; fail a switch or link
Workflow and users	Basic rack-request workflow; audit log; user rights levels	Users and permissions, tags, file attachments	No asset or change workflows
Liquid cooling, tokens per kWh	Not on the public pages	Not on the public pages	Liquid sheet with leak what-if (estimated); Token layer per server and rack

“Listed” features are those on each project’s own pages on the date checked; this is not a review of how well they work.

Project status, checked 27 October 2026

• openDCIM. On 28 April 2026 the maintainer added a “Maintainer needed” note to the README: after nearly 20 years, contributors are invited to take over the project as long as the code stays open source; a final release, 26.01, will be packaged, and the opendcim.org domain will be retired when its registration expires. The newest release on the download page is 23.04 (15 October 2023); the GitHub CHANGELOG lists the changes for 26.01, and the repository had commits in October 2026.
• RackTables. racktables.org lists 0.22.0 as the latest stable release, dated 15 February 2022 in the project’s ChangeLog. The GitHub repository has commits from June 2026.

Cost at 10, 20 and 50 racks

Racks	openDCIM licence	RackTables licence	DC Sim Monitor (per year)	DC Sim Design (one-time, if you plan a room or row)
10	$0	$0	$600	$490
20	$0	$0	$1,200	$490
50	$0	$0	$3,000	$1,490

The open-source tools cost a server and someone’s time to install, patch and back up them; that depends on your setup and is not in the table.

When openDCIM or RackTables is the better fit

• You want a free, self-hosted inventory you own under the GPL, and someone on the team will run a PHP and MySQL server.
• openDCIM if you document power paths down to the source feed and its panel and feed outage simulation answers your what-if questions.
• RackTables if IP addresses, NAT rules and load-balancer configuration should sit next to the racks and devices.

When DC Sim is the better fit

• You want the failure answer across power, cooling, liquid, fire and network on one 3D model, with estimated thermal impact, not only the power path.
• You are planning before you buy hardware: Design mode checks U, weight, breakers and cooling and runs an N−1 audit on a room or row that does not exist yet.
• A small data center or colocation room that wants a published price per rack and a 30 % margin for the MSPs and integrators who serve it as partners.
• You run an AI room and want tokens per kWh per server next to the power chain.

Moving your data, or using both

• Into the template. Export racks, devices, connections and power from either tool to CSV or Excel. Both keep their data in MySQL, so a query works; openDCIM also has a Data Center Asset Report in Excel and API routes. Map the columns to the template’s Racks, Devices, Cables and Power sheets: Devices needs only rack, U position and model per row, header names are matched with synonyms, and rows that cannot be read are listed instead of blocking the import. How to document your data center in Excel walks through each sheet.
• Keep a free inventory. If you move your records to NetBox (open source under Apache 2), DC Sim reads a NetBox site directly with a read-only token and re-syncs with a change list (NetBox, in 3D).
• There is no direct openDCIM or RackTables connector; direct connectors exist today for NetBox and Zabbix only.