Is CODESYS Development System better than Eclipse 4diac IDE?

CODESYS Development System ranks higher in our list of PLC programming software (#1 against #6, score 92.5 against 75.0). CODESYS Development System is best for: multi-vendor IEC 61131-3 controller projects. Eclipse 4diac IDE is best for: distributed IEC 61499 function-block control.

Which is cheaper, CODESYS Development System or Eclipse 4diac IDE?

CODESYS Development System: Free-marked version in the CODESYS Store; full licenses need a dongle. Eclipse 4diac IDE: Free under the Eclipse Public License 2.0.

Do CODESYS Development System and Eclipse 4diac IDE run on the same platforms?

CODESYS Development System supports Windows. Eclipse 4diac IDE supports Windows, Linux, macOS.

Comparison · PLC programming software

CODESYS Development System vs Eclipse 4diac IDE: which is better in 2026?

CODESYS Development System92.5#1 in best PLC programming software

Eclipse 4diac IDE75.0#6 in best PLC programming software

CODESYS Development System ranks higher in our list of PLC programming software (#1 against #6, score 92.5 against 75.0).

How we rank Share

92.5
Editorial score
75.0
1
Platforms
3
Yes
Free to use
Yes
No
Open source
Yes

Which should you choose?

Choose CODESYS Development System if you want

Multi-vendor IEC 61131-3 controller projects.

All five IEC 61131-3 editors and object-oriented programming in one Windows development system, with a runtime set up on each target device. Full licenses use a hardware dongle.

Choose Eclipse 4diac IDE if you want

Distributed IEC 61499 function-block control.

Open-source IEC 61499 IDE for distributed function-block control, under EPL-2.0. It targets IEC 61499 rather than IEC 61131-3 PLC languages, so classic PLC projects need another tool.

The main differences

Only Eclipse 4diac IDE runs on Linux.
Only Eclipse 4diac IDE runs on macOS.
Eclipse 4diac IDE is open source; CODESYS Development System is not.

Side by side

	CODESYS Development System	Eclipse 4diac IDE
Score	92.5	75.0
Rank in list	#1 of 6	#6 of 6
Price	Free plan, paid upgradesFree-marked version in the CODESYS Store; full licenses need a dongle	Free and open sourceFree under the Eclipse Public License 2.0
Free to use	Yes	Yes
Open source	No	Yes
Platforms	WindowsWindows	WindowsLinuxmacOSWindows, Linux, macOS
Made by	Not stated	Eclipse Foundation
Languages	FBD, LD, IL, ST, SFC	IEC 61499 function block networks
Runtime target	Any device with a CODESYS runtime	IEC 61499 devices, FORTE runtime
Simulation	Not stated on the site	Not stated on the site
Best for	Multi-vendor IEC 61131-3 controller projects	Distributed IEC 61499 function-block control
Strengths	All IEC 61131-3 editors in one development system Object-oriented programming in the IEC editors Runtime set up on each target device	Eclipse Public License 2.0 with public source Distributed IEC 61499 function block modeling FORTE runtime for devices
Limits	Full licenses are tied to a hardware dongle Development system runs on Windows PCs	Targets IEC 61499, not IEC 61131-3 PLC languages Some prebuilt builds, such as Apple Silicon macOS, were listed as coming soon
Links	Visit site	Visit site

Questions about CODESYS Development System vs Eclipse 4diac IDE

Is CODESYS Development System better than Eclipse 4diac IDE?: CODESYS Development System ranks higher in our list of PLC programming software (#1 against #6, score 92.5 against 75.0). CODESYS Development System is best for: multi-vendor IEC 61131-3 controller projects. Eclipse 4diac IDE is best for: distributed IEC 61499 function-block control.
Which is cheaper, CODESYS Development System or Eclipse 4diac IDE?: CODESYS Development System: Free-marked version in the CODESYS Store; full licenses need a dongle. Eclipse 4diac IDE: Free under the Eclipse Public License 2.0.
Do CODESYS Development System and Eclipse 4diac IDE run on the same platforms?: CODESYS Development System supports Windows. Eclipse 4diac IDE supports Windows, Linux, macOS.