Oh Euler, how do I love thee? Let me count the ways.

1. Install from hand. 1, 2. The classic. Solid, reliable, maybe a little boring, if we're honest.
2. London Library. 1 or 2, 0. Only leaves you two clicks to do your actual runs, but if you wanted to only spend one click, you could always combo it with...
3. Test Run. 1, 3. Now we're talking. Pull it from the stack or the heap and then, next turn, install it all over again.
4. SMC. 0, 4. Not always the best use of a card that guarantees your program will stay installed next turn, but it does at least let you drop it during a run, when you absolutely do need it.
5. Rejig. 1, 0. Is your used Euler looking a bit tired and overworked? Allow one of our trusted engineers to reset the mileage counter for you!
6. Simulchip. 0, 0. If you've still got Euler installed this is an even more efficient Rejig. But it's even better when...
7. Aesop's Pawnshop + Simulchip. 0 and a net 3 gain. Ohhhh yeah. I can't wait to not spend that money I just gained because my breaker is just too damned efficient to need it.
8. SDS Drone Deployment. Thanks, I didn't actually want to keep it installed anyway.

With my lost saints. I love thee with the breath,
Smiles, tears, of all my runs; and, if Corp choose,
I shall but love thee better after flatline.

I'm pretty sure this card is broken. Pelangi is already a good card, and when you combo with Cybertrooper Talut Euler becomes an absolute monster on the turn it is installed. Add in Rejig, Compile, Sumulchip... Free runs for days.